Walther RM8 regulator assembly O ring replacement.

When my Walther RM8 Varmint started leaking I decided to strip it down and replace all the regulator assembly O rings.

[@scouse1967]

Outstanding and extremely well put together instruction video. Peter. I've not long just purchased an RM8 in .177 (with the full length barrel) after having to return the first RM8 in .22 with the shorter barrel i first purchased a couple of weeks ago back to the gun shop due to the bolt handle kept working loose, which even lock thread could not keep the bolt handle from coming loose. Now after watching this brilliant video of yours i'll know how to replace all those "O" rings should my gun develope a pressure leak of any kind. Thank you so much, bud.

[@Sp3ktral22]

Such a clear description of what to do. Great!

[@Disinterested1]

thank you sir! I am planning a larger capacity tank and as it will be apart I may as well do a full rebuild on the regulator too! great info without the fluff have a great day :) best wishes

[@johnwhite9175]

Great video just brought one myself I like your sling 👍

[@noskanow]

www.ussrhouse.co.uk/products/embossed-ornament-black-leather-rifle-sling-shotgun-air-gun-strap-hunting-shooting?variant=42384924967071

[@johnwhite9175]

Thanks so much.

[@andybeckett4480]

Another comment regarding the rebuild. I recommend using loctite 572 thread sealant on the regulator cap. It's a proper gas sealant rather than a threadlock. My first attempt with regular loctite 243 blue threadlock didn't hold up under pressure. The 572 has to be cured for 48hrs or so, but it fills the relatively coarse threads and does the job. It's also easy to disassemble again. I rebuilt my Varmint in 2020 and it's shot 11.4 - 11.5 ftlb consistently ever since.

[@noskanow]

Thanks Andy, fair point and good suggestion if anyone has to buy the thread locker/sealant. I happened to have a bottle of Loctite thread lock so used it and the gun is still leak free, but as you say, getting the reg cap off again if required might be a struggle!

[@REDLION0044]

Great video, this is a common failure of these otherwise excellent rifles. I had mine repaired by a gunsmith last year but now I will be confident to do the repair myself should I need to. Thanks.

[@joetucker561]

How much did you pay? Don’t fancy doing it myself!

[@Ragnor-the-Viking]

@@joetucker561 I think the going rate is £120

[@FarringtonDS]

Thanks Peter - clear and logical instruction, I can follow this - when I have to! :0)

[@enra72]

Thanks peter this video has really helped would not have attempted this before watching.

[@brynybach7741]

A very good video with an excellent explanation of your takedown. Many thanks. 👍

[@scottwallace458]

Thankyou. My rm8 been on the shelf for a year picked it up today to fill and woosh stripped it down to find the vent leaking on the reg. Afyer some panicked searching sompkaces want 150quid for a replacement complete unit I found this. Very clear.

[@DansRandomVids458]

Brilliant vid mate. Thanks

[@tonchecker]

Excellent video, cheers man

[@MJSherwood]

Thank you so much for this. What a clear and helpful video

[@michaeloffen7513]

Excellent video thanks

[@ROBERT6500MK2]

Cracking little video this and very well explained. 👌😉

[@deltic5514]

Great video wish i watched it prior to forking out £1560 for a new regulator. My o ring as yours had vanished.

[@noskanow]

I hope you mean £156!

[@trebor4460]

Excellent 👍

[@MrGoluman99]

very nicely explained.

[@grantbaker6709]

Excellent 👍 thanks for the info

[@bobtuck575]

Excellent!

[@dahrecki6252]

Many thanks. Super.

[@penguinclips9551]

Thanks 👍

[@MrHITACHI75]

Good video Only problem I had was getting the regulator open it was very very hard to open and I snapped the Main Valve spring they are very fragile.. If you can get a better tool to open it would suggest that instead of using drill bit and centre punch.. And it's very difficult now to get the spare part as they want to sell the whole unit instead of the Main valvepin Otherwise good instruction

[@stephenpowell3737]

Thanks for the video, Peter; I replaced the tread lock with a gasket sealer when putting the reg fittings back. I got confused with the different colours o rings which looked like they were made of nylon, so I didn't replace those. Put all back as per taking it apart; unfortunately, I moved the points on the gub screws :(. I got it down to the range last week and noted the power was well down; it's pushing out only 3-foot lbs, so i guess I need to tinker with the grubs and move that collor about.

[@noskanow]

It's a pain when that grub screw collar gets moved. Mark the position of the collar with a felt tip each time you go in and adjust it. That way you can sort of guess how much to move it each time to get the power where you want it. I set mine to give 10.8 ft lb at 200 bar which seems to be a sweet spot on this rifle, deadly accurate at 30m.

[@stephenpowell3737]

Thanks @@noskanow I'm guessing that you wind it away from the regulator to increase the output, I'm only getting 3.2ft lb. Before replacing the seals and messing up the output, I was super happy with its performance even at 40 yds, I also have I BSA R10 SE and to be brutally honest I feel the RM8 is better value for money.

[@stemc83]

Just ordered an RM8, this is really useful to know. Thank you very much! How long had you had the rifle before the O ring disintegrated?

[@noskanow]

I've had the gun for about 4 years but I had a hip replacement operation which stopped me shooting for about a year, and I didn't depressurise it. So it stood in a cupboard for a year with 150 bar in it and I guess eventually the O ring just gave up.

[@stemc83]

@@noskanow thanks very much, best video I've seen on KZbin about the internals of the RM8!

[@ianmcnulty3279]

I had mine 18 months. Please see my comment at the top of the page

[@andybeckett4480]

One point to be aware of. If the air is leaking from the vent hole in the body of the hexagonal brass regulator, then the problem is definitely with the reg. If the air is leaking back out of the fill port however then the problem is with the inlet valve under the large flat headed screw on the inlet block. This has two 'o' rings, one directly under the screw head, the second on the valve body Look out for the spring!

[@noskanow]

Yes exactly, thanks Andy. That's why if the gun is leaking at all then it's best to replace all the O rings and not try to establish which one(s) need changing. If one or more have gone then the chances are there are other weak ones in there somewhere. The gun is still holding good pressure after I did this a year ago.

[@andybeckett4480]

@@noskanow Hi Peter, I rebuilt the reg. on my RM8 a couple of years ago and replaced the other 'o' rings as a precaution, so was a bit miffed when it started leaking air from the charge port yesterday. When I disassembled the inlet valve however I found a tiny speck of brass swarf under the valve piston - probably from a brass charging probe I'd guess. Just enough to create a leak path. 'O' rings were sound but I replaced the larger 8 x 1.5 anyway as it's generally damaged when you bleed off the air. problem solved.

[@noskanow]

@@andybeckett4480 Yes, at the pressures involved the slightest spec of dust on a O ring is enough to create a leak and I should have said in the video that it needs to be done in as dust free environment as possible. Your hands need to be spotlessly clean and a human hair in amongst it all would be like a tree trunk. I agree than when you use the bleed valve and it pops the top O ring then that O ring is finished and should be replaced.

[@paulodamota5259]

Hi Peter. I have the same problem with my rotex but I don’t know how to fix it. Would you be able to help me?

[@davekendrick7231]

Does the small o ring that’s disappeared on your gun sit over the lip next to the washers or just push onto the end? I saw a small hole so I’m thinking it doesn’t need to block that. Great video though.

[@noskanow]

It fits onto a recess on the end. See this drawing spares.bagnallandkirkwood.co.uk/wp-content/uploads/2020/11/Walther-RM8-Online-Diagram_compressed.pdf

[@georgeliakopoulos604]

Excellent video, very informative. Any idea where one can find a list of the O-rings used in the gun? Especially the bleed screw ones are a pain, as they blow out every time the bottle is degassed.

[@noskanow]

I've only ever seen the O rings for this gun sold as a complete set. They are available on Ebay and Bagnall & Kirkwood in UK sell the set too. Yes the bleed screw O ring does pop if there's a lot of pressure in the system, but when that is the case it's best to depressurize by unscrewing the gauge a bit. That works fine too and doesn't pop any O rings.

[@georgeliakopoulos604]

@@noskanow Thank you Peter.

[@yamatonadeshiko4537]

Can anyone tell the sizes of all orings of our Walter.i have some leak problem in my air gun and need to change orings.please help me

[@yamatonadeshiko4537]

I’m from Philippines anyway.thanks

[@barrycarruthers]

Brilliant video thanks. Can you tell me please, what washer do I need for the piston shaft, the one that you had missing, I have the same problem not sure what washer to get? Thanks Barry

[@noskanow]

I don't think the O rings can be bought individually. You will have to buy the complete set and then select the one that fits the piston.

[@barrycarruthers]

@@noskanow thanks Peter

[@rajivkotwal]

great video. thanks

[@Wolverineverminshooting]

I'm guessing you took it apart and back together before the video. The bit the barrel sits on was on wrong way round

[@noskanow]

Yes I did, and yes it is. It's not a structural component, it's cosmetic to fill the gap between the barrel and the regulator and I just prefer it that way round, but well spotted!

[@davekendrick7231]

Another great video would be to adjust the power after working on the gun to keep it legal in the uk.

[@noskanow]

My understanding is that the video would not be allowed because naughty people could use it deliberately to make their guns illegal. When I replaced all the O rings in this gun I turned the power adjustment the wrong way trying to get it to around 10.8 ft lb which is a sweet spot for it. It tested 15 ft lb after this mistake, and that would be the problem with such a video.

[@kiltedmonster1]

Peter where on earth do you get the little drelin washer seal inside the regulator? i can't find anywhere to get one and have a leaking gun.

[@noskanow]

Sorry, I'm afraid I don't know what you're referring to.

[@jasonlox27]

fab i csn fix mine now

[@shanebagley1917]

Cracking little gun. Great video. Do you know how to up the power

[@noskanow]

You remember those two grub screws I said not to touch............

[@bobgroves5719]

Hi Peter, thanks for the great Video. Unfortunately i've taken the securing pin out but the barrel won't budge. it will turn a half turn but absolutely no forward movement, any ideas mate.

[@noskanow]

Not really. There are just two O rings on the barrel which should pull out under moderate pressure. You might try putting a couple of drops of silicone oil around the joint and leaving it upright to seep in for an hour. As far as I know the barrel should just pull out, there are no other restraining mechanisms, just the pin you've knocked out.

[@bobgroves5719]

@@noskanow Thanks for the reply Peter, I thought as much, I'll give the oil a go, thanks again.

[@thejudge1075]

Maximum Gunsmith at work! I think after watching that Im ok with parting £120 to get it done by someone professional. Lol. If i tried this id of blown a hand off, lost some parts, and took it to the gunsmith to put it back together again. 😅

[@The2k11danny]

Try the bottle first make shore its tight as me and my grandad did all this to find was only the bottle needed tightening up haha.

[@duchungtran3560]

Hi, thanks for great video , just like know where I buy all the 0 rings they are different sizes .

[@noskanow]

spares.bagnallandkirkwood.co.uk/product/walther-rotek-rotex-full-o-ring-seal-kit-ref-rtx/

[@christonkin3749]

Peter, at the end of your video you state the piston end is missing an O ring which is the reason for your leak. Can you confirm where exactly you mean as I have a seal below the ridge before the washers but i'm not sure if there should be one on the other side of the ridge closer to the end as you described. Thanks

[@noskanow]

Please go to this link to see an exploded drawing of the Walther RM8 showing where alll the O rings are. spares.bagnallandkirkwood.co.uk/wp-content/uploads/2020/11/Walther-RM8-Online-Diagram_compressed.pdf

[@christonkin3749]

@@noskanow Thanks Peter

[@fecacs9532]

@@noskanow THX!

[@MJSherwood]

Hi did you remove the valve from the buddy bottle? I need to replace an o ring on it and can not get the thing to budge

[@noskanow]

No. I just removed the buddy bottle from the regulator as shown in the video.

[@MJSherwood]

@@noskanow no worries thank you. Can't find any info on it and worried it might be a reverse thread. Thanks again for the video it's helped me a bunch!

[@woodyrascel]

can you please post a link to where I can get all the replacement O-rings for this?

[@noskanow]

spares.bagnallandkirkwood.co.uk/product/walther-rotek-rotex-full-o-ring-seal-kit-ref-rtx/

[@Plentisaki]

Hello mate! Excellent vid by the way :-) I may have missed it, but what was the Vaseline for? Cheers.

[@noskanow]

You didn't miss it, I forgot to mention it! It's for lubricating the O rings, but some may disagree with Vaseline and say that only pure silicone oil should be used. I have never had a problem putting a very fine smear of Vaseline on the O rings though.

[@Plentisaki]

@@noskanow Ah righto! Thanks for the reply :-)

[@jimhatch1638]

@@noskanow Vaseline is just about the worst thing you can put on Orings. The clue is in the name. It actually over time eats your Orings. They will go soft and squidgy. The thing to use is silicone grease. Jim

[@ianmcnulty3279]

The other name for "Vaseline" is petroleum jelly DO NOT USE PETROLEUM PRODUCTS AT ALL this can be very dangerous I have a friend who used it on the seals of his hand pump and it diesel-ed at around 2000 psi USE ONLY SILICONE GREASE with compressed air (he survived but was shaking for about 30 minutes) lesson learned

[@frankmenardi2827]

I attempted to have a go. Now my regulator is permanently ruined with the piston bit broken off whilst trying the punch hole and screwdriver twist off which by the way did not work. People, please do not attempt this. I now have a useless gun which I now have to throw away as I can’t afford a replacement regulator. Absolutely gutted. Should have taken it to a gunsmith for repairs. I am so annoyed with myself for thinking this was possible. Absolutely gutted beyond belief, this is the end of my air rifle hobby. 😢

[@Nittytash]

Hi peter,is there any chance u could send the link for the full o ring replacement kit mate,thank you .

[@noskanow]

spares.bagnallandkirkwood.co.uk/product/walther-rotek-rotex-rm8-full-o-ring-seal-kit/

[@greg7728]

Hi do you know the size of the o ring needed . I'm struggling to source one that works. Thanks

[@noskanow]

You need to buy the complete complete O ring set for the gun then just replace like for like. Select the O ring from the new set which is the same size as the one you're replacing from the gun. Don't be put put off by different colours. Some O rings in the gun are green or red, but the new set will probably all be black. Just replace same size for same size and you'll be fine.

[@greg7728]

Top man thanks

[@joesps4channel697]

Superb video buddy, could you tell me how the vasaline is used on this replacement, appreciated thanks

[@noskanow]

To lubricate the O rings. You could use silicone oil too, but in either case only a very very light coating on each O ring before they are put in place.

[@joesps4channel697]

@@noskanow thanks, that's great

[@LumisArms]

For the love of god dont use vasaline!! It degrades orings!! If you want your repair to last longer than 6 months use silicone grease only!

[@noskanow]

Hear what you say and respect your view but.........2 years on and the gun is holding pressure fine, I shoot it every week at my club and no problems at all with the replacement O rings. If the O rings were still made of rubber then I'd agree with you, but these are neoprene and petroleum jelly is fine with neoprene.

[@fatbelliedpenguin]

Please can you tell me where you got the o ring kit from 👍

[@noskanow]

spares.bagnallandkirkwood.co.uk/product/walther-rotek-rotex-rm8-full-o-ring-seal-kit/

[@karolzambrano3561]

Hello Peter. I have the same problem with my RM8. Would you help me change the O rings please or do you recommend someone near London that can help? Thank you

[@noskanow]

I am not a professional, insured repairer and therefore would never work on anyone else's air rifle even if I could. If you don't feel confident enough to do this yourself then my advice is don't ask a non professional to do it for you. If you don't want to do this yourself my very strong advice is to take or send your gun to a registered professional repairer in your area and I've just done an Internet search and found 10 of them in and around London. Good luck.

[@karolzambrano3561]

Thank you Peter

[@johndoherty8681]

Hi don’t suppose you know why I would have air leaking out of the quick fill body as I have replaced the seals in the regulator but can not under stand why it would leak out of fill port

[@noskanow]

The fill port has two O rings in it, one at the top and one buried right down at the bottom. Did you replace both?

[@johndoherty8681]

@@noskanow yes replaced the one at the top but did not see the one at the bottom mind really frustrated mind as the air dose not seem to be going in the bottle but straight out the top of it

[@noskanow]

@@johndoherty8681 You need to replace both of them on the fill port. The fill probe has two O rings on it as well. Have you checked them?

[@noskanow]

Click on the picture. spares.bagnallandkirkwood.co.uk/walther-2/walther-rotek-rotex-rm8-r8/

[@johndoherty8681]

@@noskanow yes changed them two , I have orders a full new seal kit for it so I think I will strip the gun right down again and replace them all and grease them all right up

[@annward2254]

Hello peter having a bit trouble with my gun in your video you say ther are 2 o rings in the filling gauge i only have one in mine.could you please tell me the one i have missing is the same as the one thats in.👍🏻

[@noskanow]

There are two O rings on the fill valve vent screw. There is one O ring on the fill vale pressure gauge. Not sure about your terminology here Ann. Please look at the drawing I posted to one of the other questions here which shows where all the O rings are on the whole RM8 system.

[@annward2254]

Was me t to say 2 orings on the fill valve vent screw bloody gun got me stressed lol mine has only one in the fill valve screw peter not sure what other o ring goes in is it the same as other one.thanks

[@noskanow]

@@annward2254 This is difficult at long range!. Please look at the drawing I posted the link to. You'll see that the vent screw has an O ring at its thread end which is larger than another O ring which sits at the bottom of the vent screw inlet. These two O rings are different sizes, the outer one larger than the inner one. Again, please look at the drawing and you'll see this.

[@annward2254]

Got it peter thanks very much great video and helpfull dont know how i have ended with one o ring in the fill valve vent screw

[@noskanow]

@@annward2254 I'd be surprised if there was only the outer O ring there. Are you sure the inner one is not there down at the bottom. You might not be able to see it easily and it wouldn't fall out, you'd have to pick it out.

[@Dandroid5000]

I just tried disassembling my regulator......ended up snapping the piston!!! Someone had already bodged a repair, by the looks of things. There were clamp marks on the regulator body, and the two holes on the piston end showed signs of a previous battle! Whoever repaired it must have used an entire bottle of thread lock.....I was locked in an arm wrestle! It was so tight that I ended up damaging my workmate, bent one of the drill bits.....aaand eventually the spanner slipped, shearing the piston! Really disappointed with Walther for using such a low quality regulator on what is actually a pretty decent rifle.......why on earth did they decide to use brass?!?

[@noskanow]

That's really bad luck and I can well understand your frustration. It's a bit harsh to blame Walther though. The RM8 regulator is as good as any and better than most and had yours been in original condition you would have opened it fairly easily and certainly short of bending a drill bit! I think the person to blame is the one who bodged the previous attempt.

[@ianmcnulty3279]

Hi Dandroid5000 Try a small amount of heat from a small blowlamp (this destroys the thread locker) not too much enough to make it uncomfortable to touch should do, but there is nothing in there you will damage only the O ring but as you are replacing that anyway it wont matter. hope this helps for next time

[@andywebster8617]

Good video but no the regulator can’t be took apart as easy as in this video I had to stop my attempts at either end before it got really damaged ,I had a vice ,spanner’s, heat gun 3.5mm bits etc etc but it just would move and the brass started to chew up and I was worried about snapping the pin

[@noskanow]

Sorry that you had difficulty opening the regulator. I've had several people tell me they did theirs as in the video without any trouble. You could buy the special tool and try doing it with that, here's the link. spares.bagnallandkirkwood.co.uk/product/walther-rm8-main-valve-regulator-opening-tool/

[@andyduncan5772]

Where did you get the o rings from? I’m struggling to find anyone

[@noskanow]

Bagnal & Kirkwood search rm8 o rings

[@noskanow]

Bagnal & Kirkwood search rm8 o rings

[@andyduncan5772]

Thank you

[@22Brat22]

Thanks for the detailed video. I have a similar problem. Rotex RM8 starts leaking air exactly after filling to until 2k PSI. If I fill to 2.5k PSI, it will leak to 2k PSI and work normally after that. I am unable to precisely locate the source of the leak, however it sounds to be somewhere near the regulator. PS: there is no air escaping from the hole on the regulator. The bottle o-ring is fine. Any idea what could be the problem?

[@noskanow]

If you're certain there's no air coming from the regulator vent hole, (put your tongue on it to make sure), then the buddy bottle end of the reg is probably OK and the air is probably leaking from the firing chamber at the front of the reg into the barrel. Given this situation I would try replacing just the O ring at the front end, the one at the thread-locked end of the reg as in the video. To do that you needn't touch the rest of it, but please do make sure you depressurise before you open it up. If there's quite a lot of pressure in the system it may be best to depressurise by unscrewing the gauge a bit rather than by undoing the fill port vent screw. Bagnell & Kirkwood sell the full O ring set, just type RM8 spares into their search box.

[@22Brat22]

@@noskanow Thanks, I am going to try this over the weekend. I have bought the full Walther RM8 O-Ring set from eBay.

[@enra72]

@@22Brat22 how did you get on did you fix it yourself ? I'm thinking of trying to fix it myself to

[@22Brat22]

@@enra72 I changed all the seals as shown in this video, but it still kept leaking. There are few more seals on this regulator that is not shown on this video, I went to check those and at that time I had dismantled the regulator at least thrice and unfortunately on my fourth attempt the regulator split apart at one end. I learnt that the Brass regulator was not designed to handle the stress. I was using a spanner and vice. I still haven't found a replacement regulator :(

[@enra72]

@@22Brat22 I'm sorry to hear that. I have heard parts can be difficult to get hold of, frustrating that something as simple as a O-ring can cause so much trouble.

[@mrg7919]

How do the washers stack? ()()()() ?

[@noskanow]

Yes like that. They act as a very stiff spring.

[@CROWENshort]

()()()() how many joule?

[@davesanderson703]

can this regulator be adjusted at all

[@noskanow]

@@davesanderson703 Yes of course it can. Most regulators of this kind can be adjusted either to a sweet spot which on mine is 10.7ftlb which gives me deadly accuracy up to 40m, or up to illegal power. I'm not going to say how because I don't want to help anyone to do the latter.

[@davesanderson703]

@@noskanow ah right ok that was my next question on how do i adjust it just mines firing at 9.3 ft

[@noskanow]

@@davesanderson703 Sorry, But I'm not going to say on here how to adjust the power.

[@chen119750]

Please tell me the o ring size.

[@noskanow]

You don't need to know O ring sizes. Buy the complete set and replace them size for size as you go. spares.bagnallandkirkwood.co.uk/product/walther-rotek-rotex-rm8-full-o-ring-seal-kit/

[@chen119750]

Thank you

[@andyfry745]

Would have been informative…but had to switch it of because of that fucking mind numbing background constant tsp😵😵😵😵

[@noskanow]

I'm so sorry that my beautiful 150-year-old American old wall clock irritated you to that extent. I did think of stopping it for the video but no, why should I, it's earned its right to tick away. The only thing I can add that you appear to be in a minority of 11,167 to 1 so I think the clock has it.