Total brake failure.

Today my brakes failed no warning at all.
The brakes on my 2001 TD5 none ABS 110 were very good but today pulling up at a set of traffic lights nothing at all (no major issue were able to stop using the gears and hand brake)
On inspecting it, the nearside rear caliper seal failed, Ok so the brake fluid is released from this caliper (all squidged out making it easy to see a fault) and subsequently the offside rear brake will be starved of any pressure due to the rears are fed from one pipe.
I believed the system was a tandem system, whereby I should still have some braking on the front wheels but nothing. I did try jacking one of the front wheels my wife applying the brakes which went to the floor and then me spinning the wheel some resistance was present but I could still turn the wheel.
The master cylinder has three pipes leading from it and two chambers in the reservoir both of which still had brake fluid in them and not at all low enough to be an issue.
Is there something else at fault in the system as well as the rear brake calliper?

id get a new master and pair of rear cailpers stc1268 and stc1269 around 30 quid a piece

jamesmartin said:

id get a new master and pair of rear cailpers stc1268 and stc1269 around 30 quid a piece

Click to expand...

Thanks James Do you think the master cylinder is the fault of total brake failure?
I am correct I should still have had some braking shouldn't I?

that was my thinking, you should have a little pedal as m/c is 2 in 1

OK James that's good to know. New master cylinder and two rear calipers it is then.

I thought a110 should have a pressure differentil warning actuator valve situafed between master cylinder and front and rear brakes the valve has a electrical switch connected to warning light on controle panel the purpose of this valve is if there in one leak on one circuit piston will move across blank off leaking circuit giving full power to other circuit

8ha said:

I thought a110 should have a pressure differentil warning actuator valve situafed between master cylinder and front and rear brakes the valve has a electrical switch connected to warning light on controle panel the purpose of this valve is if there in one leak on one circuit piston will move across blank off leaking circuit giving full power to other circuit

Click to expand...

My 110 is fitted with a pressure reducing valve (PRV), fitted to the RH bulkhead in the engine compartment, it maintains the braking balance front to rear. Pressure
to the rear calipers is regulated by the PRV, this valve is of the failure by-pass type, allowing full system pressure to the rear brake calipers in the event of a front (secondary) circuit failure.
No electrical connections giving a warning light, there is a low fluid warning light from the master cylinder. This uses the same dash warning icon as the park brake on warning. My issue was the rear caliper seal failed, yes it spit out fluid at the rear but not enough to cause the low fluid light to come on and the front brakes did not work.
I am at a loss to know why NO front brakes when the rear seal failed.

thanks for your reply is it possible valve has stuck or become faulty can you strip valve I have not had any experience with with this valve when you fit new parts could after bleeding brakes could you leave one front bleed screw slightly loose to simulate front brake failure press pedal hard and hard hard and see what happens would it be worth contacting main dealer in case it is a know fault or has there been a recall on this part please excuse splling left school 60 ago if you like experimenting with things you could get old master cylinder out in vice bleed both ports then block off then leaver as hard as possible see if it holds up or does it creep if it does not creep you could try releasing pressure in one port and then the other one to see if either one creeps under pressure you could strip cylinder and inspect all parts another thaught befor you take off old master cylinder take off both brake pips bleed cylinder screw bolts to block ports then try as above to see if it creeps under pressure if you van not find bolts to fit you could use 2 old /new brake pipe nuts find right size ball bearin g and use them to block ports or you could fill pipe nuts with weld /braze etc being careful not to damage thread if you have acess to taps and dies you could tap thread thread in brake pipe nut and screw in small bolt to blank it.it seems very strange for both cylinders in master cylinder to go at same time

Just an update on this issue;
I have replaced the two rear brake callipers and pads (taken the opportunity to replace rear axle brake pipes) fitted a new master cylinder and new front brake pads. Bled the brakes and all is working well, I did release the rear nearside bleed nipple after attaching a length of pipe to simulate a piston seal failure and the front brakes were still working but I did have extended peddle travel but never the less I still had front brakes.
Now investigating the issue I had whereby I had no brakes at all.
This is what I believe is the events which resulted on no brakes. The rear calliper piston seal failed but failed a while ago, the area around the leaked fluid looked like road grime and brake pad dust had contaminated the area but none on the tyre where I would have thought it should have been (could this have worn off?).
The front calipers and discs were no older than 5000 miles and working well along with the vehicle not having been loaded at any time just lately it stopped and stopped well enough so that I felt no issues.
When the total brake failure occurred it must have been the master cylinder failing on the one system I already had no brakes on the other system because of the rear piston seal failure.
I have tested the master cylinder and sure enough only one system is working.
No issues with the brakes at the last MOT which was November so the rear seal failure occurred since then.
I may be wrong in this diagnosis but it is how I feel things went belly up.

thanks for imfo8ha brake fluid is water soluabel so rain may have washed it off wheel