Club Triumph

Hello,
Been driving arround town with my new 1300 TC, and sometimes the brake pedal gets hard and the brakes are engaged ... weird ... a simple touch of the pedal get rid of the problem but it is quite disturbing.
It usually happens after a good stroke on the brake pedal, then when it returns it blocks ...

the servo is fairly recent, no leaks ...

Any idea ?

one of the brake flexi rubber hoses is collapsing internally and acting as a non-return valve?

or possibly something happening with the master cylinder - although these are pretty simple

Ok is there some braided hoses for the TC ?

Should be possible to get some made up if no-one sells a kit.

I would suspect the servo though.

disconnect it and block the pipe on the manifold to prevent it messing up the mixture.

1300's didn't have a servo and all teh other parts were identical so teh brakes will still be OK, just heavier.

Cheers

Colin

I think the fronts may be the same as Dolomite?

I've experienced the same problem in the past with a remote servo on a 1300 ( not a TC, but retro fitted ) just disconnecting the vacuum won't necessarily cure the problem as it may be a sticky hydraulic valve in servo.

If it's the original Girling servo there should be a small air filter on the top by the vacuum pipe, check this isn't blocked.

But that doesn't mean the problem doesn't lie elsewhere, it's well worth changing the flexible hoses anyways, unless you know they're fairly new

you mean the little white "hat' ? how can I check it is blocked ?
Any idea where to find those flexihoses ?

Canley hasn't got any braided hoses for the FWD.

I suspect also the air valve sticking ...

Hello, sorry haven't had a computer for two weeks. Dolomite brake hoses do fit , I have a pair of braded hoses on mine although I've had them so long I can't remember where they came from but all the usual suspects must do them. Incedentally the rear hoses are the same part number as the Herald/Spitfire so I recently bought a braided pair for the back too, though I haven't fitted them yet so I can't absolutely confirm that they fit.

I now have a Lockheed servo on my car too as the original Girling Powerstops were getting scarce and unreliable. I've had no trouble with mine so I don't really know how it works, though the symptoms do sound like servo related, though I'd go for the hoses first - cheaper and easier!

This sounds like the master cylinder non return valve is knackered. To rule out servo issues just disconnect the servo and use the brakes like that - remember all a servo does is reduce pedal pressure so remember to compensate when driving. After you've found there's nowt wrong with the servo you can rebuild the master cylinder with a service kit :-) I had a very similar issue on the PI, brakes would come on almost randomly, I chased that issue for a long time before stripping the master cylinder and finding the culprit.

Thanks gfor the inputs !
I'm away from the car now, will report the progress when I'm back.
G


oh, is it a 0.625" brake master cylinder ?
and is it Dolomite Sprint front hoses or just Dolomites ?

I'm back on the problem ...

Hello,
Been driving arround town with my new 1300 TC, and sometimes the brake pedal gets hard and the brakes are engaged ... weird ... a simple touch of the pedal get rid of the problem but it is quite disturbing.
It usually happens after a good stroke on the brake pedal, then when it returns it blocks ...

the servo is fairly recent, no leaks ...

Any idea ?


I took off the vacuum pipe ( blocked it ) and the problem disapeard ...
It is a Lockheed unit, it seems to be a sticking something inside ...
Someone have an idea ?

Apart from knowing it should be a Girling not a Lockheed...

I would suspect there is a sticky valve in the servo not allowing the vacuum to disappear, or perhaps the pipe has collapsed internally.

As it does not do it with vacuum hose disconnected it has to be the servo.

Time for a replacement?

mmm yes maybe time for replacement ...
seems to be the bullet vlave that is sticking ...
Also it seems that it is not mount the right way compare the this drawing (pics of my car in the start of thread):


this to prevent air lock ...  :-/

one simple basic not discussed is make sure there is some free play on the master cyl pushrod, if the pedal is partly siezed it wont allow recuperation and you get a build up of pressure, giving the pedal a stab may just allow release.

remove the servo plastic cap and the filter and clean the rubber air valve seating inside

I have know these servos to hang on after application and no amount of seal kit or head scratching will solve it , but thats a last option

always check the simpleze first.

Pete