Brake servo woes
Brake servo woes
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Discussion

Rockettvr

Original Poster:

2,020 posts

173 months

Monday 3rd June 2013
quotequote all
Evening Peeps
As per the title my brake servo is on its last legs- Too much pedal travel and slowly sinking ie: losing vacuum probably due to the corrosion on the underside.... could some one let me know what the servo is off and possibly point me in the direction of a new one please. smile
Thanks in advance
Ron

Jack Valiant

1,894 posts

266 months

Monday 3rd June 2013
quotequote all
Before you start replacing he servo check the slave and master cylinders. ..

Any loss of fluid?
Any fluid on the pedal?
Is the fluid in the resovoir black?
When you press the pedal does the fluid in the reservoir lower?


All indicate seal failure iether in the master with fluid getting past the seals same in the slave, tired fluid with moisture / air in the system.

Chris

Rockettvr

Original Poster:

2,020 posts

173 months

Monday 3rd June 2013
quotequote all
Hi Chris
The symptoms are thus:-
No apparent fluid loss
Pedal travels a long way before brakes start to bite
If sitting at lights etc with pedal depressed it slowly sinks until almost on floor
If pedal depressed and then ignition turned off the pedal gets harder and pushes up against your foot
Under normal use after braking the pedal returns to normal position only slowly not springing back straight away

Not had a chance to inspect for anything else this evening as at work today I managed to put a pretty deep slice into the index finger of my left hand with a stanley knife!!

Any thoughts? Any help appreciated smile

The servo will need to be replaced anyway regardless as its very rusty on the underside so I need to know what its from also. Many thanks All

Danny Hoffman

1,617 posts

292 months

Monday 3rd June 2013
quotequote all
It sounds like master cylinder to me

RCK974X

2,521 posts

179 months

Monday 3rd June 2013
quotequote all
Yeah, me too. if the servo was faulty, then the pedal would get really hard to push.

Sinking pedal means Mcyl seals are probably worn. The Mcyls don't always leak...

Take mcyl off the servo (2 nuts) and I'll bet it's wet with brake fluid at the back of Mcyl.
or check the 'drain' (there's a hole underneath on the MCYl flange - try testing with a tissue)

Been there, but I had a very slight weep down the servo from drain, which was a dead giveaway.
New seals fixed it.

Rockettvr

Original Poster:

2,020 posts

173 months

Tuesday 4th June 2013
quotequote all
Thanks chaps
Looks like master cylinder then.
What's the master cylinder from ?
Should I repair or buy a recon cylinder?
The servos definitely had it too what's it from ?
Thanks Ron

RCK974X

2,521 posts

179 months

Tuesday 4th June 2013
quotequote all
Early wedges (2.8, like mine 1982) are definitely Cortina Mk4 or 5, both servo and Mcyl

I think later wedges went to Rover SD1 ? not sure -

Someone like Wedg1e will know !! (hint...)

Mcyl is Cortina, ref PMF226, 20.6mm dia, 3x10mm outlets. Haven't got servo ref no

Anything within reason should work around the 20mm dia, provided it fits....

I wondered about a Sierra one (22.2 mm), but would have slightly firmer pedal

I reckon the TR6 setup from my Vixen S3 might even fit, apart from the UNF threads that is....


jon haines

960 posts

276 months

Tuesday 4th June 2013
quotequote all
I agree with others as i have had the same in the past and it was defo the master cylinder. dont mess about with seal kits or re con get new. my experience of seal kits is they dont last long and difference between new and re con isnt enough for me to bother with. got mine from RT Racing

Mr Tank

5,799 posts

305 months

Tuesday 4th June 2013
quotequote all
Hi

I agree fit new master cylinder they only cost around £45-£50 new from dealers or F-bay!

Andy

Rockettvr

Original Poster:

2,020 posts

173 months

Tuesday 4th June 2013
quotequote all
Thanks everyone for the help thumbup