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+--- Thread: brake problem with my special (/showthread.php?tid=1813)
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brake problem with my special - ThomasSwiss - 30-09-2018
Hello
All four hydraulic brakes on the test bench are ok
But the Austin pulls to the left when braking hard
what is the problem? the brake fluid is exchanged.
(the problem existed before the exchange)
I can not find a solution.
Thanks and Greetings
Thomas
RE: brake problem with my special - Stuart Giles - 30-09-2018
Have you tried putting the front brake drums on opposite sides? i.e. left to right; right to left. If so, did the problem stay the same?
RE: brake problem with my special - Dave Mann - 30-09-2018
I was plagued with this on a Seven back in the early 1970s, with all new parts, linings, cylinders, etc and under heavy braking I didn't know which way it would go, certainly not in a straight line. I eventually found that the linings were too hard and which ever lining heated first is the way it would pull. The solution was to replace the linings with a softer type.
RE: brake problem with my special - Charles P - 30-09-2018
Can you post a picture of the front backplates and pipework please.
Charles
RE: brake problem with my special - GK5268 - 30-09-2018
Assuming that your hydraulic brake components are all stock Morris Minor, it is possible that you have air stuck in a wheel cylinder, which could make one side fractionally more responsive than the other (as well as shoe adjustment - assuming the linings are an axle set and not a mixture).
The orientation of one of the pair of front wheel cylinders to each side with the piston facing upwards means that air can be trapped as the in/out drilling is at the lowest point. Not a good design!
When I bled my brakes, I have taken the back plates off the stub axle and laid these horizontally to give the air the best chance of air being expelled. You could also remove the pistons from the wheel cylinders and pour brake fluid in to prime it first, a bit messy and air could still be trapped under the lip of the seal...
Also worth checking is the clearance between the brake shoes and the wheel cylinder fixing mount (the small nut end) as these can push the shoe too far over (just a fraction) and this will affect the adjustment slightly, but enough to give rise to uneven braking, this can also make the shoes bind on the drum.
The adjusters should be turned by the same amount, but if the drums have unevenly worn this may not be the case, adjuster turned to lock the drum and then backed off one or two clicks so that the drum rotates freely without running against the shoes.
I had murders setting up my front brakes after fitting new parts and I examined each part to see what was causing problems and all that was required was a little gentle filing off the casting by the wheel cylinder fixing mounts and this allowed the brake shoes freedom to properly centralise, all resolved and job was a good-un!
RE: brake problem with my special - Alan - 30-09-2018
It’s caused by the brake torque deflecting the front spring, combined with the somewhat flexible radius arm mounts. This allows the top of the axle to move forwards under braking, this pulls on the steering arm, and the result is a left pull. Well, that’s the easiest way I can describe it. To fix it, you need to fit a simple strut, each side between the top of the axle, close to the king pin eye (or even to an extended king pin) and a point halfway to the rear of the radius arm. I don’t have a picture to hand, but this has been talked of before in this forum. A search should find it.
RE: brake problem with my special - Terrytuned - 30-09-2018
Brake tie rod (photo attached)
RE: brake problem with my special - Charles P - 30-09-2018
(30-09-2018, 11:35 AM)GK5268 Wrote: I had murders setting up my front brakes after fitting new parts and I examined each part to see what was causing problems and all that was required was a little gentle filing off the casting by the wheel cylinder fixing mounts and this allowed the brake shoes freedom to properly centralise, all resolved and job was a good-un!
I've had the same problem with pattern parts being rather crudely made and came to the same solution.
As for air in system if the car pulls up straight after a quick double pump on the pedal it's air.
Charles
RE: brake problem with my special - ThomasSwiss - 06-10-2018
Hello everybody
have worked through your suggestions ... without success
Brake pads have been dry and dry for years, oil-free
Brake drums were never interchanged, the bias came slowly
Reinforcements are appropriate.
Thanks for your help
Thomas
RE: brake problem with my special - Tony Press - 06-10-2018
(06-10-2018, 06:23 PM)ThomasSwiss Wrote: Hello everybody
have worked through your suggestions ... without success
Brake pads have been dry and dry for years, oil-free
Brake drums were never interchanged, the bias came slowly
Reinforcements are appropriate.
Thanks for your help
Thomas
Is the toe in correct- the track rod end doesn't look to have been adjusted for years ?