Club 80-90 Forums

don`t worry I have been searching....

when I was coming down a hill in the Pyrenees ,the pedal went to the floor ,so I had to pump it to work ,I did have a look for air leaks and could`nt find anything...drove back 200 miles and everything was fine...

8 months later the same has happened ,drive normally and 20 minutes later develop foot to the floor syndrome...

So I am going to order...

2 x rear cylinders

4 flexi hoses

the brake fluid has probably been in there years, so that might be the problem ,I hope...

do I need to order anything else?

dandaz wrote:the brake fluid has probably been in there years, so that might be the problem ,I hope...

That'd be my first port of call in the circumstances. The fluid's old, "wet", so the boiling point's much lower than it should be. You might get away without replacing any hardware, but seized nipples are possible, and the water in the fluid will certainly have shortened the life of everything through internal corrosion.

Change it every two years - and don't forget the clutch.

When I redid my cylinders and hoses, I fitted new bleed nipples all round and had to replace the solid pipe on the tailing arms.

When I had to service my rear brakes I ended up replacing the solid brake lines as far as the "junction box" on the rear crossmember. I found that the pipes were seized solid to the flexies. You may need new clips to hold the new brake pipes too. Measure the lengths of brake pipe you need and your local motor factor will make up the required lengths for you (well mine does).

It's called Vapor lock, caused by the brake fluid boiling and gas bubbles forming under extreme heat.....gas is compressable where as brake fluid isn't.
Vapor lock is much more likely as the brake fluid ages and 'takes on water'... brake fluid being 'Hygroscopic' which means it absorbs water from the atmosphere.
Just 3% water contamination lowers the boiling point by 100 degrees centigrade.
DOT 4 has a dry boiling specification of around 240 C so you can see how drastically it is affected by a small amount of water contamination.

Don't go replacing components....just strip and lube, make sure everything is moving freely (especially the front calliper pistons) and completely BLEED those brakes with nice new DOT 4 fluid.

Martin

Unlike other fluids, brake fluid needs changing regardless of mileage....infact the vehicle may not have moved 10 feet in two years but still needs it's fluid changing. All the time it's sat there water is leeching past the seals and resevoir cap even though on the face of it everything is air tight.

Martin

lloydy wrote:When I redid my cylinders and hoses, I fitted new bleed nipples all round and had to replace the solid pipe on the tailing arms.

cheers ,I will check all my nipples before I start...I am quite used to changing the system on a t2 just never done a t25 ...

Thanks for you replies..

If it took me 8 months to look at the brakes after the pedal first went to the floor think i might be receiving a T25 recommended maintenance schedule in my crimbo stocking as wellas a right ear'oling

I notice the warning light on the handbrake stays on ,does that point to something?

The light is controlled by either: the switch on the handbrake lever (has the bracket bent, is it missing the striker?)
Or
A brake fluid level switch in the reservoir cap (they don't all have these but most do). So has the brake fluid level dropped below the minimum mark on the reservoir?

Martin

cheers, I will have a have a look...

sticker?

The reservoir was empty but no wire on the cap....

I could`nt see any leaks....

Warning light still on...[after filling the fluid and going for a spin]

where is the handbrake switch?