300Tdi brake servo test. Bad brakes and excessive back pressure?

[@johnlippiatt8200]

Great video as usual Mike. I have replaced the servo on my 300tdi twice now, it has 260000 miles on it so not too disappointed. One thing which I think you could cover which doesn't seem to be in any of the workshop manuals is servo actuator pin adjustment. The most recent unit that I fitted this was well out causing a very low pedal and sudden brake feel. Explanation of the setting up may well help many of your followers. 👍

[@BritannicaRestorations]

There should be no reason to adjust the pin - yes it gives a better pedal - until the brakes heat up, and the expanded fluid, can no longer return to the reservoir as the seals shut the return off - this can result in the brakes overheating, so for liability I do not offer this advice I hope you understand

[@johnlippiatt8200]

@@BritannicaRestorations Clearance on the unit I most recently fitted was 30 thou from the manufacturer, I had never had to adjust one previously on a Land Rover or any other vehicle. Not shown in any manual that I could access in the end I had to make tool to measure the clearance. Once set all worked correctly, fluid returned to reservoir , no overheating now been functioning OK for 12000 miles. Understand your point regarding liability, do you want me to delete my post?

[@BritannicaRestorations]

No - don't delete - but you can see it is a very fine line between good brakes and dangerous = I have seen someone's vehicle lock up the brakes completely due to over adjustment after driving round town This is why there is no mention of this in the manual

[@petermenzies1714]

Absolutely brilliant explanation and crystal clear illustration of the cause of this quite common problem. Tdi’s will now be more expensive when panic sellers begin to realise t’s the brake servo not the engine which kaput and pressuring the crankcase.

[@DTS1838]

I learned something there Mike ,great video ,thank you.

[@BritannicaRestorations]

Glad to hear it

[@teivatehevini2101]

Thank you Sir ! It's interesting for me because I've got à defender 90 300tdi 2006 march

[@BritannicaRestorations]

Enjoy it!

[@TheNorthernExplorer]

Great info! After your advice on the previous video I’ve ordered a second hand unit to see if it fixes my problem. I also have an issue with oil out the breathers so this could be the root of all evil! Thanks for the info!

[@Reaper4367]

Great information as usual Mike. My breaks are good, for about 3 seconds on the pedal then the pedal starts to drop towards the floor. Cheers for sharing.

[@BritannicaRestorations]

Good stuff!

[@lukeevans9698]

Thanks!

[@BritannicaRestorations]

Welcome!

[@davidforbes6250]

Gooda Michael.

[@berndeikers8924]

Would be evt. Helpful to know how many years thie booster was in service, how many and what services have been made? The problem of the booster is huminity getting in and doesnt come out. That means rust, that means the material gets weaker

[@MARTINA-gc3tq]

Many years ago, a pal was working on his TR6 which had a brake issue. His servo was cracked and he repaired it with glass fibre mat and what I assume was epoxy. He often worked on his glass fibre speed boat so I wonder if he got the idea from that.

[@BritannicaRestorations]

I have seen plastic servos in the past -- after market, but I never see them now

[@AngusAbbott-qf8xm]

Thanks for this and I will make a copy in case my partner asks about my wanting my vacuum developer in the toolbox

[@BritannicaRestorations]

Lol!

[@PeasantPrep]

Having issues with the servo on my d1 getting engine oil in. This is the second servo this has happend too so going to change the vac pump aswell. Im guessing there is a one way valve that may of failed.

[@BritannicaRestorations]

Maybe - the engine takes air from the servo, but does not pump air in from the engine

[@scottthomasmartin]

With these servo issues, do you think it's a bad idea to connect the breather to the intake? Should the hose off the breather terminate somewhere else so that we don't get oil in the intake pathway?

[@Mike-yq6jg]

Besides the servo what else can cause back pressure

[@BritannicaRestorations]

Bad piston rings/scored cylinders/damaged pistons. Very bad valve guides Bad head gasket

[@andrewk6844]

I had one on mine last vehicle , Just put silicone over the cracks

[@Mike-yq6jg]

When I us a hand held vacuum pump I can only get around 10bar ,is the servo good ?

[@BritannicaRestorations]

Can you give a measurement in mm/mercury (mm/HG) or inches of mercury (in/HG) please 10 bar is 145 PSI

[@jameskerr5756]

Interesting Mike. Mine looks as though it has been changed not too long before my ownership so seems to be still good. Presume it would be the same symptoms on the V8.

[@BritannicaRestorations]

You should be OK as it should have the older style servo - much thicker

[@cdnrover]

Geez, I didn't know it was not working properly mate. No symptoms, good break and no excessive back pressure. The master cylinder never needed topping up. Might be a consequence of all those years driving old Land-Rovers, you get used to bad car!

[@BritannicaRestorations]

See why I like to test parts! ?

[@berndeikers8924]

Didnt you say brakes worked find over years. Doesnt Sound Like a Bad car to me ...

[@jamieambrose893]

Fighting a few battles with my 300tdi d1. And I have watched that many of your videos now I can here you taking when am working on it 😅 good videos mate keep it up! Good proper videos with none of the 🐃💩

[@smifflarr]

Could this be the case with any car or just specific to land rovers?

[@BritannicaRestorations]

Any vehicle with a servo/booster

[@alfredsteidle5035]

Thank you for this excellent Video😊. Maybe you can show us the inside or the Membran ? Is the rubber good ? 👍👍👍👍👍👍👍

[@BritannicaRestorations]

I have a video somewhere when I stripped a servo - but there is not much in them and every one I have looked has been cracked - never experienced a diaphragm broken

[@alfredsteidle5035]

👍

[@jonbuckley1495]

25 years on mine, it's original too, worth changing?

[@BritannicaRestorations]

Hard to say - may have been changed in the past?

[@jonbuckley1495]

@@BritannicaRestorations I have a rare example where Ive known and have the full and complete service history since it was new from the showroom, was unwanted as the TD5 was due to be released for sale the next month

[@alanhowatson3462]

I changed a cylinder head out once for excess back pressure, only to find out the servo was kaput!

[@BritannicaRestorations]

Easy done!

[@alanhowatson3462]

@BritannicaRestorations it was something you mentioned in one of your videos about how the 300tdi servo was thin and prone to cracking that led me to the servo. So thank you Mike. Top bloke👍

[@BritannicaRestorations]

Yes an easy trap to fall into! Even happened to me!

[@peter8828]

would 2part epoxy work ?

[@garypoulton7311]

No, might work for a while, but would crack, as the whole plate flexes. One cure only: new servo

[@BritannicaRestorations]

Correct

[@peter8828]

@@garypoulton7311 or sell the landy and buy a land cruser lol 😂 (Sorrry)

[@berndeikers8924]

​@@peter8828... Here WE Go ..

[@erictyrrell3560]

200Tdi booster may have been the last one made of sufficiently thick metal

[@BritannicaRestorations]

Indeed - the TD5, disco and puma seemed to be made of sterner stuff

[@erictyrrell3560]

@@BritannicaRestorations so only the 300Tdi was a weak design? Haven’t seen the later ones.