Brake Pedal Will Not Return Under Servo Assist

Hello!

I have a 1986 MK1 GTI Cabrio and as the title suggests, the brake pedal will not return under servo assist. The pedal stays to the floor, the brakes stay on, but release when the pedal is lifted manually. However, when I disconnect the vacuum hose from the servo unit, the brakes operate as they should, albeit without servo assist so are quite hard to operate, but the pedal returns by itself at least.

Is this likely to be an issue with the servo unit itself, or the non return valve, or both, or something else?

Any help would be much appreciated!

Dave

Sounds as if the return spring in the m/c or your pedal assembly is broken.

Ya'll with the RHD do things a wee bit differently than we do on the LHD side of the world.

To me if it works with no vacuum assist then that is usually a broken MC spring to me.

Now the question I have to ask, did this start after you repaired it, or just on it's own.  Why, because if you replaced a defective MC, and the issue started, then you have either a bad MC (I have gotten 2 bad rebuild in a row for a original bad mc,) and I decided to buy new…

Or if you replaced the MC, and tighten one side down, then the other you have had tweaked the pressure rod off the booster.  You have to take both nuts down equally 5 turns left, 5 turns right.

I would post a picture of it but the htread on the vortex is got the photobucket bankout.

Thanks for your reply. In answer to your question, I bought the car 4 months ago and have been fixing it up since and this was an existing issue. It had be stood for several years and the master cylinder/servo do not look like they have be touched for quite some time!

I have already replaced the return spring in the attached pic a this did not make any difference unfortunately.

How would I tell if the return spring in the MC is broken?

Well in my trials removing it and then depressing the plunger is the only way I know of.

I know that y'all have a way of Rube Goldberging the thing to RHD, and I am not familiar with that at all.  

I do know that making my LHD MG Midget or AH Bug-eye RHD was a whole lot easier….  

I am bothered by that photo.
1. It looks clean.
2. The cotter pins aren't bent to prevent them from falling out. MAJOR ISSUE TO ME.
3. That is a torsion looking device and it may not have enough tension to hold the pedal up. Similar to our Tension rodded Garage doors that you have to use a bar to get the torsion correct on the thing.

Better RHD minds will comment……

Ok, I will get the MC off and investigate. Thanks for your comments.

The cotter pins… I haven't bent them yet just in case I need to remove the spring to take the servo unit out