Doc Harley’s caution for Twin Cam projects

[@MichaelDay-cs4gj]

Wow, I know the process of hydraulics but never thought of that one. Man!!!!! Gonna start cleaning out holes better than ever. Thanks

[@LowCountryHarleyDavidson]

It's always good to learn something new. Glad you found this useful…Doc

[@RNintheTrenches]

Priceless education in under 5 minutes, thank you Doc. Happy New Year to you and your family!

[@LowCountryHarleyDavidson]

Thank you for watching and the Happy New Year wishes…Doc

[@jasonshortphd]

Fantastic tip. I wouldn’t have thought about that. I know it logically, but I wouldn’t have thought that the casting would pop.

[@PSK66az]

Thank you for sharing all you years of experience! Saving us 100's, 1000's of dollars and all the frustration

[@Peter-976]

Excellent tip Doc!! Thanks

[@bongorick]

Thank you, for all you do to keep us on the straight and narrow path.

[@darrell3368]

Thank Dr Harley keep up the great shows and tips ps Gods blessings to you and all your family

[@LowCountryHarleyDavidson]

I truly appreciate the blessings…Doc

[@billcarson1966]

That's amazing but scary information! Wow! I could easily see that happening to me and I'm very thorough and careful in my approach! Then again, I typically leave the advanced stuff to the pros. Good stuff, Doc!

[@thomasdurante3084]

Good advice for sure, as a former toolroom machinist learned to blow out holes/especially threaded ones for debris/dirt/coolant/liquid on fixtures, fittings, assemblies, it prevents headaches in future

[@LowCountryHarleyDavidson]

Thanks for sharing your experience...Doc

[@maddog3080]

Thank you for trying to save us from costly errors, greatly appreciated!!!

[@edharbas4828]

Thank's, again, Doc. As usual, a couple of visuals and your synchronized diologue, a real helpful piece of cake. Cheers all around with that beer.

[@LowCountryHarleyDavidson]

I appreciate you watching and your support….Doc

[@Dave-he9uq]

I learned this lesson the hard way back when I was a new tech. I used Permatex Ultra-Gray and everything was fine luckily. Now I fill all the holes with brake-clean and blow out with compressed air.

[@LowCountryHarleyDavidson]

Lessons in life stay with you forever…Doc

[@hazepennington9303]

Great info DOC Harley , I recently did the heads on my twin cam for the first time and I was lucky to spot this problem in time I also found out another place is the cam cover and oil pump bolt holes where oil will puddle up into some of the holes , I clean the holes out with a Q-tip and Yes it's a great idea to always clean out any holes on your motorcycle that collects oil before threading any bolt into them , that could save a person a headache , time and money.. Thanks alot DOC Harley 👍💯

[@edharbas4828]

Thanks for the pointer.

[@gregrose6915]

That is a very valuable important tip. Thanks Doc. Happy new Year

[@LowCountryHarleyDavidson]

Happy new year Greg…Doc

[@stevemamooshka3425]

This makes me wonder if screwing in that bolt very slowly would let the oil seep past the bolt threads. Of course, getting the oil out with a couple Q-tips would be a whole lot faster.

[@LowCountryHarleyDavidson]

Threads don’t go all the way up the bolt…Doc

[@jerrylong381]

Thanks for the tip, Doc. Nothing hurts the heart like installing a bolt and hearing a "POP!". It's amazing how much force can be generated by a 1/4"-20 bolt on a confined fluid. I learned my lesson years ago when putting the primary cover back on my 73' Sportster after rebuilding the clutch. I'm spinning the bolts in with a tee handle allen wrench, just bringing up to contact when I hear the "POP", and I see old silicone coming out of a crack in the case like little blue hairs growing before my eyes. My heart dropped to my toes. Luckily the crack was just between the bolt hole and the outside of the case. I was able to put sealer over the crack and finish the summer before tearing it down and getting it welded. That was the day I became religious about cleaning the threads on every bolt and bolt hole I deal with. The previous owner was a big fan of silicone, asI discovered when I rebuilt the motor. But the damage was my fault for not being meticulous in my work. Silicone is not oil, but they behave the same when put under pressure with no where to go.

[@edharbas4828]

Conversely, would, say, a 1/32 drill hole through the centre of the fastener help by allowing pressurised trapped oil to escape as it was being fastened? The drill hole could be cleaned out of old sealant if need be. Mind you I do realise a cotton bud would be a lot easier, just barn-storming. Cheers

[@jerrylong381]

@edharbas4828 I clean them out with the correct size tap and then blow it out with compressed air. I've never had a problem after doing that.

[@LowCountryHarleyDavidson]

Thank you for taking the time to post your experience….Doc

[@grahampawson1502]

Brilliant tip doc, could save a fortune in repairs 🤙🏍👏👏

[@randybard224]

Been there done that I heard it break I found the piece that broke off Cleaned it up / jb weld it in place. A little thread sealant on the bolt 80+k on the repair never leaked Lesson learned Now I blow every single hole out with air no matter where on the bike it is!!!

[@LowCountryHarleyDavidson]

Thanks for sharing Randy….Doc

[@rayss3323]

Great reminder to clean out ALL blind holes. Thanx!

[@jefffrayer8238]

I agree with the repair you did. Sealant on threads stops the oil seaping down and J. B. Weld makes sure. No pressure there.

[@susandavis5833]

Thanks Doc. I'm about to put mine back together and didn't know this.

[@LowCountryHarleyDavidson]

Glad you caught that before assembly…..Doc

[@jamesskinner1101]

Thank You Doc Harley! And thank you for taking time to meet and talk with me.

[@LowCountryHarleyDavidson]

You’re very welcome and a pleasure to talk with you…Doc

[@davidscottcurtiscurtis775]

I live near pig trail Harley-Davidson in ar. Greatly appreciate information on twin cams 04 fxti and I realy love it.

[@LowCountryHarleyDavidson]

Thanks David….Doc

[@samrotolo7303]

Thank you for the reminder I dont think I am taking that serous enough. I have a rear rocker gasket leaking/weeping and I read to clean out oil from holes but I have now made note in my service manual for when I decide I am going to fix my bike.

[@LowCountryHarleyDavidson]

You're welcome, good luck with the project…Doc

[@dougfresh1341]

A Service Manual!! The tool most DIY guys won’t invest in.

[@williwichtig9344]

Hi Doc, thank you very much for this. It's a brillant information for everyone doing it for the first time. Greetings from overseas, Germany 😉✌️

[@LowCountryHarleyDavidson]

Thanks for your post from Germany…Doc

[@montanaguy]

Great post, AS ALWAYS, Doc. Thank you so much and Happy New Year!!!! Me and my Twin Cam can't thank you enough!!

[@LowCountryHarleyDavidson]

Thank you for watching and support…Doc

[@jeremyankney1733]

First one I broke it popped really loud and an oil mess everywhere. Expensive mistake. Now I do exactly what you said. 😊

[@arnoldschachat]

Excellent tech tip Doc!-I upgraded my breathers a couple of years ago and did not check your tip-I must of been lucky or just used break cleaner to clear the holes.

[@LowCountryHarleyDavidson]

Glad it worked out for you….Doc

[@alveus8205]

Wow. Such a small thing can lead to a big problem. I did mine a few years ago and cleaned the bolt holes so the loctite would adhere better. I’m glad I did!

[@LowCountryHarleyDavidson]

Well done….Doc

[@tamayo991]

FYI: The new head breather kit comes with shorter bolts but you still need to clean those holes out.

[@MarshallParsley]

Thanks Doc. I’m making a note of it right now in my service manual.

[@Rollie396]

As soon as I saw the thumb nail I knew what this vid was about lol I’m amoung the meatheads that did this. I heard a little plink sound when I tightened that bolt and I learnt a lesson that day. I mixed up some jb weld on the end of a popsicle stick, smeared it around the underside of the casting and let it cure. That was 12yrs ago and I haven’t had the leak since….I’m also sure to blow out blind holes now before threading a bolt into it.

[@LowCountryHarleyDavidson]

Thank for sharing your experience…Doc

[@user-vr2tx4tt6b]

This is why these videos are so great. Thank you, sir.

[@LowCountryHarleyDavidson]

I appreciate your post….Doc

[@RiseNRip]

Just in time Doc! I'm doing this job on my bike next week and didn't know this.

[@LowCountryHarleyDavidson]

I'm glad I could help…Doc

[@greenmarine5]

very good point Doc, liquids can't be compressed so something has to give. 👍👍

[@kmeades43]

That's a good one Doc. Thanks for the great advice. Ride safe from Sydney Australia 🤘

[@LowCountryHarleyDavidson]

Glad you enjoyed it…Doc

[@67Screwy]

Brilliant thank you Doc

[@scottlint7016]

I just blew a bolt out when replacing the breathers. I threw gasket maker into the hole and tightened down. Good to go, zero issues since.

[@LowCountryHarleyDavidson]

Any chance you carry a 4 leaf clover with you?…..Doc

[@rsbharley4766]

Excellent tip Doc, thanks for taking the time to share. Cheers

[@michaelmcclendon2466]

Ty Doc good info Happy Christmas and have a great New Year keep your videos coning

[@LowCountryHarleyDavidson]

You're welcome, happy holidays to you as well…Doc

[@hdbikerdave5835]

Thanks Doc. Merry Christmas and Happy New Year!

[@LowCountryHarleyDavidson]

You too, and thanks for watching…Doc

[@stlchuckhd]

Ouch! Thanks for the video Doc!

[@jeffmorrison5274]

Thanks for Tips and I never knew about this... you are man DOC ! Have a happy Holiday !!

[@LowCountryHarleyDavidson]

Thanks. Happy New Year….Doc

[@joeharley87]

Another good tip. Happy New Year Doc.

[@LowCountryHarleyDavidson]

Happy New Year to you too…Doc

[@dannymanny6917]

Excellent. Thank you for the heads up.

[@LowCountryHarleyDavidson]

Thank you for watching Dan…Doc

[@gordonmiller7246]

Hanks for the tip as always Doc. Great job.

[@LowCountryHarleyDavidson]

You are welcome Gordon…Doc

[@nvpoolshooter]

Excellent. This begs the question, what are the symptoms that your breathers need replacing?

[@LowCountryHarleyDavidson]

Take the time to find one of our earliest videos on this question….Doc

[@h.d.mech.mortenson2098]

Hope you had a great Christmas Doc. Happy new year !

[@LowCountryHarleyDavidson]

Happy New Year to you as well…Doc

[@neildewitt2869]

Merry Christmas 🎅 Doc from Alaska!

[@johnpinkos2144]

Great advice & tech tip, thanks for sharing.

[@LowCountryHarleyDavidson]

Thank you for watching John…Doc

[@shameless5868]

Preciate that tip doc. I never gave that a thought.

[@doylehenderson319]

Thanks Doc for a very valuable tip!!!!! That's working like a brake line.... you can compress air but not liquid. I hope you and the family had a great Christmas together and wishing you a Happy New Year!!!

[@LowCountryHarleyDavidson]

You are very welcome, and happy new year…Doc

[@dieselsoggydog6299]

At the moment you said the bolt started to slow down but still goes in, I guessed oil was in the whole. Simple air gun to cleaner it out works. Can't believe that casting can break with that light of torque. Those bolts do look like they are longer than they really need to be.

[@Dipndots87-ms6ds]

It’s not so much about the torque of the bolt as much as the hydrologic pressure. I did some tests years ago with different cast aluminum pieces like aluminum differential cousins and aluminum cylinder heads on small engines. I put different gasket maker and different viscosity oils on the threads and in the hole in different amounts. What I found was the smaller the width of the hole, the faster the casting craked. The overall depth of the hole wasn’t as important as the hole diameter. Obviously this was just some bs test I conducted with scrap parts but it really opened up my eyes on how fast things can go bad when we aren’t paying attention to the little things. No go out and get you some scrap pieces and start destroying stuff in the name of science!

[@dieselsoggydog6299]

@@Dipndots87-ms6ds I was going off the math. With a 6.35 mm bolt with a drilled hole surface area of 0.3167 cm2 and 1.3 Nm of force on the bolt. It would only develop 6.23 psi of hydraulic pressure. Correct me on my math if I've missed something.

[@dieselsoggydog6299]

@@Dipndots87-ms6ds Went and did the math. With a 6.35 mm bolt with a drilled hole surface area of 0.3167 and 10 to 16 Nm of force on the bolt. It would develop around 45-70 psi. It would break it if the casting was thin enough.

[@donpet8258]

Very useful info !! Thanks much !! I just had mine replaced. I’m glad the Harley dealer did it now. !!

[@tommontague5721]

Never knew.....Thanks Doc

[@GIGABACHI]

Holy Crap. Way to ruin your day in the most innocent way thinking your are doing yourself a favor while learning something new. Thanks for the heads up ! Very important info.

[@scottlin777]

Thanks for another great video doc.

[@LowCountryHarleyDavidson]

Glad you enjoyed it Scott…Doc

[@Lem-HDtech]

Did it on 1 of my first jobs 😢 Cleaned and silicone was a good temp fix until we got a new one to replace it. Lesson learned. Great tip, always love the videos ❤

[@LowCountryHarleyDavidson]

I know that feeling from my early days…Doc

[@Lem-HDtech]

@LowCountryHarleyDavidson Indeed. Live, and learn 😍 Best to you and yours. Hope you had a good Christmas season.

[@paulprosser4108]

Another excellent tip Doc. Hope you continue to educate us home mechanics. Hope you have a good New Year.

[@LowCountryHarleyDavidson]

Thanks, you too…Doc

[@johnschoonmaker-tm3ll]

Great info, have noted it in my service log. Thank for posting this video. 👍

[@LowCountryHarleyDavidson]

Thanks for watching John….Doc

[@willtopower2158]

Always great information Doc, Merry Christmas and Happy New Year to you and yours!🎄

[@LowCountryHarleyDavidson]

Thank you and the same to you….Doc

[@DavidLattinville]

Thanks Doc that helps out a lot

[@royogden2536]

Now that is a dang good tech tip right there. Thank you so much. 👍😎👍

[@LowCountryHarleyDavidson]

Thank you Roy…Doc

[@HellOfaDay54]

Thank You Doc for that good information. when did Harley change over to the newer breathers as I know in the older twin cams they had that older breather style. which I changed to the newer style in my 01 ultra about 3 years ago. So do you know when Harley switch over to the newer style breather as I have a 2011 ultra 110 CVO now. cuz I know I could look in the parts manual to find out. but it might help others to know when they switched.

[@kiwibiker9754]

Classic! As a wiser man than me once said " a little bit of knowledge is a dangerous thing!"

[@oldamerican8070]

Thanks, Doc. , I enjoyed hearing all your advice .

[@LowCountryHarleyDavidson]

I appreciate your time watching…Doc

[@whip-its_dad4239]

That's good to know for sure . Thank you for your channel .

[@LowCountryHarleyDavidson]

Thanks for watching…Doc

[@dougk9647]

Well,.....that was a real eye opener. Thanks Doc.

[@eddybuckhalt8657]

Great tip! Thanks Doc!

[@LowCountryHarleyDavidson]

Thanks Eddy…Doc

[@canefam1016]

Thanks Doc 👏🏾👏🏾👏🏾👏🏾💯🫡

[@lukepace8546]

Great video and tip as usual Doc Harley!

[@LowCountryHarleyDavidson]

Thanks for watching…Doc

[@fearsomename4517]

Great advice Doc.

[@LowCountryHarleyDavidson]

Thanks for watching and posting. Doc

[@RodHog1]

Great video thanks hope you had great christmas and happy new year

[@LowCountryHarleyDavidson]

Thanks I did and the same to you…Doc

[@cameronbartley6139]

Wow that's crazy, the unknown.... Thanks for sharing that,what a headache that could be.

[@okiemale1589]

Thanks Doc... Thumbs up for the channel... 😎👍

[@LowCountryHarleyDavidson]

I appreciate it. Thanks for watching….Doc

[@bradduffield9603]

Great tip as always. Thanks Doc.

[@LowCountryHarleyDavidson]

You’re welcome Brad, keep watching…Doc

[@stevel7071]

Thanks for another great video enjoy the holidays

[@LowCountryHarleyDavidson]

Thanks, you too….Doc

[@flhrcanuck0927]

Thanks Doc. Wondering why you didn't just hit the holes with air. Also curious how the DEI heat shield inserts worked for the officer. Cheers.

[@LowCountryHarleyDavidson]

My dear friend. Last week we posted the officer’s review. ( not everyone has a compressor for air assist)….Doc

[@flhrcanuck0927]

@LowCountryHarleyDavidson thanks. Missed the review. Will watch.

[@MmFord45]

🤯 wow thats crazy & good to know thanks. Even though I don’t do any of my own repairs.

[@LowCountryHarleyDavidson]

Thanks for watching, you never know when you might….Doc

[@lemontier]

Thanks Doc you are appreciated big time.

[@LowCountryHarleyDavidson]

You are very welcome…Doc

[@nhrider88]

Thanks Doc. Another great tip.

[@johnsb1550]

I think I'm OK, but I'm definitely going to check that! I've always been able to thread those down all the way by hand

[@GJM866]

Would this apply to evo heads also? I'm doing rocker box gaskets.

[@LowCountryHarleyDavidson]

Yes but not blowing a hole. It will pull threads…Doc

[@GJM866]

@@LowCountryHarleyDavidson Okay, thank you!

[@dougfresh1341]

Excellent Doc.

[@LowCountryHarleyDavidson]

Many thanks Doug….Doc

[@JohnBlair-p2z]

great video. thanks for the heads up.

[@Giuseppe_De_Bellis]

Cheers from Italy, Doc!☺️

[@LowCountryHarleyDavidson]

Gracie….Doc

[@Giuseppe_De_Bellis]

@LowCountryHarleyDavidson ❤️💪🏻

[@chargerman426]

So if you move to the "new" design are the bolts from the old design comparable? The new design appears to be a lot thinner than the old ones. Personally I like to rebuild the old style ones but understand that others would rather a new one piece design.

[@LowCountryHarleyDavidson]

The new design comes with new bolts..Doc

[@qf4phlyer]

Once again, Doc, great information.

[@LowCountryHarleyDavidson]

Thanks for watching…..Doc

[@JamesHyde-tb8os]

Great word Doc!

[@LowCountryHarleyDavidson]

Thanks James….Doc

[@nealehanning4700]

Thanks, appreciate it.👍

[@alanwhiteside410]

Well now there’s a great tip! Thank you Doc. 😎👍🍻

[@LowCountryHarleyDavidson]

Thanks for watching Allen ….Doc

[@gregmcbee2585]

Thx Doc. Great to know. I'm changing mine this winter. Just saved my ass

[@LowCountryHarleyDavidson]

I am glad it helped…..Doc

[@busabobsgarage9876]

Thanks for this awesome tip!

[@leestevens4536]

Awesomeness!! Thanks for that.😊

[@LowCountryHarleyDavidson]

You’re welcome, and thanks for watching….Doc

[@stuartbuckley6113]

Happy new year 🎉 ✨️

[@LowCountryHarleyDavidson]

Happy New Year to you as well…Doc

[@davoko]

Very good to know Thanks Doc

[@danbarrette9888]

It’s all about the tricks when working on the Harley. Thank you.

[@LowCountryHarleyDavidson]

I am glad you liked it, thanks for watching….Doc

[@a.toddmoore7262]

What a great tip, thank you doc Harley!

[@LowCountryHarleyDavidson]

Glad it was helpful…Doc

[@jlc904ubc]

Thanks Doc. Great info. Great video.

[@LowCountryHarleyDavidson]

You are welcome…..Doc

[@FloridaBoilermaker]

Thanks for the warning, my 96ci thanks you also.

[@LowCountryHarleyDavidson]

Glad you got the message…Doc

[@graemejones7646]

Thanks heaps Doc!! Still a legend 🙌

[@LowCountryHarleyDavidson]

Thanks, but far from Legend just a man on KZbin….Doc

[@Jimmy_Jim_Jim_1234]

Thats a GREAT tip thanks.