BRAKING ISSUES

[WHITESTAG]

Hi Guys!

Come on D.J.T! Seaside Bill and all........! please explain why (PENNY) my 74MK2 brakes are just so poor!!!! still well spongy -fade etc

Pads are fine- got no leaks- seals ok-bled system as per my orriginal shop manual rear shoes ok etc etc.....One point of note I have noticed a fine "blackish" sediment in base of reservoir?? ....not much but am begining to wonder is my fluid losing correct viscosity etc and would I benefit fom changing?

Having said that is their any agent I can use to essentially "flush " the system with prior to re filling?

Concerned as ticket due -and know for fact the examiner(****S) ...picky lot- get my drift is gonna fail her on same!!!!

:dude:may your V8 BURBLE!!!

PHIL

[dogsnadgers]

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One point of note I have noticed a fine "blackish" sediment in base of reservoir?? ....

usually a sign of deteriorating seals - probably in the master cylinder, although possibly elsewhere if they haven't been replaced recently, I can lock all four wheels up quite easily if I want to - so you definately have somehting awry - good luck!
Dave

[WHITESTAG]

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Cheers for that! will have another nosey not sure of main cylinder- but all other seals quite new!

Considering going over to silicon based fluid after having a nosey at technical pages!

Anyone out there used same? comments appreciated

:dudehil

[DJT]

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Phil,

Definitely something amiss if brakes are that poor. Spongey brakes usually means air in the system. Are you sure you have bled them thoroughly? Is your PWDA connected and the warning light out? If not connected, then you should check it is centralised.

Some sediment is common in the master cylinder. This can be cleaned out. Changing to siliconwon't improve the braking. It is actually slightly more compressible than the ordinary.

If the system is fully bled, and PWDA set correctly, then there is the possibility you have one or more rubber hoses on the point of failing. They can bulge under pressure, which is one of the tests the MOT man will carry out.

The Stag system, although much criticised, is actually very good when working correctly. My Stag failed its MOT this week as the offside rear wheel cylinder was weeping. It only showed up on the brake tester - the brakes seemed fine on the road. Luckily my local Partservice had cylinders on the shelf so I was back for a certificate by lunch time .

Dave

[Malcstag]

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Hi a good idea to change brake hoses to steel braided, older hoses ballon slightly when presure applied. Makes a big difference. You can swop to dot 5 without problems, a higher boilng point, didnt fail me at castle coombe track, dot 3 boiled over.

[WHITESTAG]

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Thanks for that Dave! going to have a nosey at all system top to toe again!! keep you posted!!!

:dude:CHEERS!

PHIL

[Handbrake5]

Just acquired my Stag. Car is very slow to pull up under braking. I have replaced the rear wheel cylinders, flexible hoses, and brake pads. Servo is working fine, system correctly bled.. Still no improvement. What else should I be looking for? Phil.

[flying farmer]

Just acquired my Stag. Car is very slow to pull up under braking. I have replaced the rear wheel cylinders, flexible hoses, and brake pads. Servo is working fine, system correctly bled.. Still no improvement. What else should I be looking for? Phil.

I have 2 Stags and the brakes on one have always been bad compared to the other. Over the years I have changed discs, pads and brake servo to no avail.

Recently I fitted new rear drums and shoes even though the old shoes were making full contact around the worn drums. Brakes are now much better. I have had the same thing happen on my TR5.

If you fit new shoes to worn drums it can take thousands of miles for them to bed in properly, best to fit new drums and shoes at the same time.

[FrenchStag]

Take off your drums and see what state the rear brake cylinders are in. They used to be cheap to replace but it’s a bit of a long job. If your master cylinder is getting on a bit, that may be the culprit (my pedal used to sink to the floor at one stage before I replaced the MC). Quite easy to swap for a new one. While you are at it, might as well get some new front callipers if your existing are old. Easy to swap, but read the manual as you have to loosen a bolt that you wouldn’t expect in order to remove. Do the flexible hoses whilst you are at it. If all that fails, might be a blockage or crud in the brakelines but if you can bleed everything easily thats not likely

[jbuckl]

Standard system is pretty good.

People often go for ‘upgrades’ …. But a restored system works well imho.

limitation is actually tyre grip.
Master Cylinders often need a sleeve to repair though so seal kit on its own won’t usually improve the cylinder for long.

either get sleeved or fit new

[Gresley]

I had similar issues when I first had my Stag. On mine it turned out that a new brake master cylinder had been fitted and the pushrod between servo and master cylinder needed to be adjusted. Since that was done the brakes have been superb with a firm pedal.