Brakes not working

[stag36587]

OK. I have replaced the entire braking system except handbrake cables. Have bled brakes many times - including at the brake light switch and no air bubbles. Have also ensured correct pedal travel at the master cylinder. No leaks from anywhere.

I have full pedal travel to the floor but there seems to be no hydraulic pressure and of course the brakes don't work.

What am I doing wrong or do you think it's a faulty master cylinder? It's a Lockheed bought from ESM and installed about a year ago. Car has not been anywhere since 1995 - the brakes are one of the last jobs to sort before going for an MOT.

Any ideas please? Other than replacing the master cylinder with another one, I'm stumped!

Many thanks for your help.

[les]

Sometimes people have not got the brake shoes adjusted up close enough to the drums.

[bmcecosse]

Could be - disconnect the handbrake cables and wind all the adjusters up SOLID. Then try again. If you pump pump pump on the pedal - does it come up solid then? If so - then your assistant opens the nipple and closes it again quickly as the pedal sinks to the floor... Start at the furthest away - ie nearside rear and work towards the master cylinder. I assume the master cylinder has a return spring attached - and 1/4" free play on the push rod....

[stag36587]

Hi yes pedal firmed up a bit when pressed several times but not enough to give anything other than minimal stopping power. Brake shoes are adjusted as they should be I think e.g. with adjuster fully on drums don't move, one click away from solid, drums turn with resistance. Bled from farthest point etc as you suggest Roy and yes got right amount of play at the pedal (took me ages to get that perfect).

Had no problems at all replacing the braking system on the Stag so don't understand why this one is proving difficult

[bmcecosse]

Well -bleed as suggested - if the pedal goes firm with multiple pressings..there is hope...

[chickenjohn]

Sometimes a Minor can be quite tricky to bleed, especially if you have unnecessary pipe work for a servo etc.

You will just have to bleed again starting from rear left, then rear right, front left, front right etc. and repeat till you get a good pedal.

Often using an easy bleed system can help, especially if you support the fluid bottle on the parcel shelf this can give some height to the brake fluid as you are bleeding.

I have found that cars with a remote reservoir fitted are much easier to bleed.

[MarkyB]

The Minor brake fluid reservoir is small by modern standards, you really have to keep an eye on it or it's back to square one on the brake bleed.
If it's taken ages to get all the air out I'd pull back the dust seal on the front of the master cylinder to make sure there is no sign of a fluid leak there.

[Sandun]

look at ur master silinder filler nut is it loose or it has good gascet ring ? Ok 1st u Remove the master cylinder oil filler nut then see oill leval , then slowly push brack paddel by ur hand , if u can see oil of Master cylinder come up , ur master silinder is fine - 2nd the good way to brack reset after change brack lines , buy a hand presher cylinder, fill it brack oill then fill ur brack lines from oill then off ur brack line nippels next connect brack lines with master cylinder - Remember the master cylinder filler cap if loose Not brack work ur car -

[bmcecosse]

Not really Sandun - I agree it should not be loose - but it honestly doesn't have any effect on the operation of the brakes...

[stag36587]

Hi guys, a brief update. I have bled the brakes again, no air bubbles anywhere, brakes still not working at all really. But, I did notice a bit of paint that at some stage had bubbled under the 3 way connector in the engine bay so that would seem to suggest a leak though it is bone dry even under continual pedal pressure. Easy enough to change the connector and front pipes and if that doesn't work then I will try a second replacement master cylinder. I have checked all pipes/hoses/connectors everywhere else (everything is brand new) and they appear to be fine.

Anyway to give myself some sort of motivation over the weekend, I checked/adjusted all suspension front and rear then replaced the torn front passenger seat base cover...

[bmcecosse]

Test the master by simply fitting dead-end pipes to it!

[stag36587]

Test the master by simply fitting dead-end pipes to it!

Yes Indeed - certainly want to do that before having to remove and replace which was a bit of a pain last time.

[bmcecosse]

To do that - just blank off the pipes leading to the front and rear brakes - either all together or just one at a time...

[kennatt]

Roy will be on after this telling you not to do it,.but its what every garage does,using the appropriate tried ,tested and approved tool .
Clamp the fexi hoses,enough to close them,but not enough to damage them,you hardly need more than just a slight nip up,use mole grips with a large coin,to spread the load,unless like me you have the sykes pickavant brake hose clamps.
Then see if you have a hard pedal,if no,then either,air in the system or dodgy master.
If yes,remove one clamp at a time and you will soon see which brake is causing the problem.

I do agree with roy, to an extent ,that repeated overuse would damage the pipe,especially on old ones which may have hardened,but if so they should be changed anyway.On new or good condition pipes ,in 40 years,neither myself or anyone else in the family garage has damaged one,but its your choice.Obviously can't be done on braided hoses.

[bmcecosse]

[kennatt]

told you so

[stag36587]

Well it's taken a month for me to look at the brakes again mainly because I was getting the Stag ready for my daughter's wedding - happy to report it performed faultlessly including traffic jams at hanger lane gyratory in London.

Anyway the brakes.... I found an old brake pipe union that I could use to
blank off the front brakes at the master cylinder. Immediately, the pedal was firm and not sinking to the floor like before. I also tested that the master cylinder was pumping a nice lot of fluid at that union too.

So I will re-examine all the pipe connections - my money is on trouble at the 3-way junction in the engine bay. I'll let you know what I find!

[stag36587]

I am losing the will. Welcome to the continuing saga of my non-existent brakes. Quick recap - the whole brake system is new - master cylinder, pipes, unions, wheel cylinders, brake shoes, etc. In view of my last post I have replaced the master cylinder to front 3 way union and also the pipe from 3 way union to offside front. only because I thought some of the bends were a bit tight.

Current situation is that I have bled the brakes yet again but still don't have a firm brake pedal though it firms up a bit after 3 pushes of the pedal. Then pedal goes spongy again after about 20-30 seconds. There is no air in the system that I can see when I bleed the brakes. So here is my plan now:

Blank off Each side of the three way union to see if that helps. I previously blanked-off the front brakes at the master cylinder and that seemed to help so still suspect a front rather than rear brake issue.

Take off each drum and see if I can see at movement of brake shoes when pedal is pressed.

Squirt washing-up liquid or similar round brake unions and look for air bubbles when pedal is pressed.

If all else fails, replace the master cylinder with another new one.

Does any or all of that sound sensible? The brakes are the only thing left to sort before trying to get an MOT for first time since car was taken off the road in 1995 by the previous owner. Can someone also please confirm correct fluid level in the master cylinder? It's currently up to bottom of the filler neck.

Many thanks for any suggestions before I call in the professionals (which I'm determined not to do unless absolutely necessary!)

[bmcecosse]

Are the brakes adjusted up HARD against the drums ?? And does any air come out when you bleed them?

[katy]

Squirt washing-up liquid or similar round brake unions and look for air bubbles when pedal is pressed.

Not likely that air will come out, brake fluid will if there's any leaks.