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Check the springs are sat in the holders correctly up against the stops in the arms and you may have to remove and refit the rubber upper mounts so they sit right.
Technical Odd brake issue.
- Thread starter Marx
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Technical Odd brake issue.
Excellent, thank you, will swap rear springs and see what happens, before we do this. Would this also happen with just the driver on board on that higher side and would that imbalance lock the front left wheel? Thanks.
Will do.
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Not certain. A driver can be 20% of the cars weight so it's possible it would make a difference.
I just thought that my weight on the higher side would push that side down more making the difference in height negligible regarding the braking issue.?
Okay more information has arisen, I've checked both rear springs and the way they are seated and they all look good. However, I thought I would check the tracking again with the gunson trakrite, and on moving the car backwards and forwards many times I have noticed that the car has moved sideways and is now at an angle in the garage with the front left being closer to the left wall than before! I have checked the rear tracking and we have at least 2.5 degrees of toe on the rear wheels unladen, I can't remember if it was toe out or toe in.....I don't know if this is anything to do with the braking issue but I would assume that the fact the car is not rolling straight and is drifting to the left after being rolled backwards and forwards and it locks the brake on the front left maybe linked? The rear arms were removed when someone rebuilt the car and when we recently changed the rear bushes we had to remove them......surprisingly there quite a few spacers/washers missing....so all we could do was add an even amount to each side of the bushes.......
Please ignore the last comment.....I thought if the car was going left in the garage why didn't it feel like it one the road.....I then had a thought. Our garage floor slopes slightly backwards, We have been pushing the car slightly up hill over the trakrite and then letting it return by itself.....from the drivers door area!! We have just pushed the car again a few times from the passenger side and it has straighten up!! Silly me.
If your car is diving to one side under brakes, you have a brake problem. If there were a weight / steering geometry problem severe enough to make it dive to one side under brakes, it would be obvious all the time the car is moving (and it seems you've covered all the geometry and condition of the steering components already, your idler arm / king pins ' tie rods aren't about to fall off onto the road). Check again that all the self-adjusters are properly functioning; they're a very simple system on these cars and unique in my experience- seems to me that if the system were 100% reliable it would have been adopted elsewhere as it is far less complex than other systems. I'd be thoroughly checking the adjustment mechanism to ensure that the shoes aren't creeping back more on one side than the other. Check the shoe return springs- are they identical both sides? Check the orientation of leading / trailing shoe- drum brakes have a 'self-servo' effect and the orientation of the shoes is important. Check that one wheel cylinder does not have a larger bore than the other due to previous overhauling. As a very much less likely source of the problem, an important part of the brake system is the grip of the tyre bead on the wheel rim. Easy to check by putting a chalk line across the sidewall and the rim and checking it's in the same place after some braking. Again, far less likely than the problem being inside the brake drum.
Did you replace any of the brake shoe retaining springs? New replacements are known to cause problems due to being slightly different in length.
Thank you for such an in depth reply. The springs are the originals and the same on both sides. Both cylinders are the same and replaced as a pair. We have swapped wheels over and the issue remains so not the tyres etc.
We have a spare complete front stub axle assembly. We will swap that over on the 'poor' braking side and see what happens.
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Thank you they springs are the originals still.
Okay an update.....we have swapped over to our old hub onto the right front which has it's original springs, shoes, hose and drums fitted....which we never had any issues with....and the brake is locking up on the left even more violently than before...
The next port of call is to swap over the left hand side hub which we have also, and see if the issue remains. I was hoping the right hub brakes weren't "adjusting" properly....but that doesnt seem to be the case.
The next port of call is to swap over the left hand side hub which we have also, and see if the issue remains. I was hoping the right hub brakes weren't "adjusting" properly....but that doesnt seem to be the case.
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I think I'd carefully check the shoes have the linings properly applied, i.e. where the friction material starts, the leading / trailing edges of the shoe. I'd struggle to give an explanation in writing, so look at where the friction material starts & ends on the two brake shoes in this picture. Check that your brakes are set up the same each side with regard to this. The non-lined area of brake shoe at the 1 o'clock position in this image is particularly important, and if it's different left / right it will give different self-servoing effect. Just trying to offer possibilities that you may not have checked.
Thank you, we will refit the hub on the right side as I know that is all new, then take the drum off the "locking" left side to see what's what.
Here's our locking side, have fitted new shoes whilst in there again.
Attachments
Another update, clamped rear hoses again as I just wasn't sure it was 100% the fronts and I couldn't see what else I could try. Car still pulled to the left with a tyre locking up.....so has to be the fronts......got my wife to stand in the road as I braked with the rear brake hoses still clamped and.....REAR left wheel locked!!! So it's definitely the rear left. Obviously I now know my hose clamps are rubbish as well!
Soooooo what is the cause if a rear left brake lock up before any other tyres?
Soooooo what is the cause if a rear left brake lock up before any other tyres?
Before we go headlong into the rear brakes now, am I also correct in thinking the usual bleeding procedure is not correct for rhd cars? With a rhd car should we start at the rear left, rear right, front left, and finally front right? Thanks
