The Camaro Club (UK)

My brakes are totally horrendous and I have to press the pedal really hard to actually stop also when I need to brake hard (especially in the rain) the rear drum brakes lock up really easy, even as slow as 25mph. The back left brake locks up first and is way way more efficient than the one on the right but since there is only one pipe going to the back which splits to feed both then I am guessing it can't be a master cylinder problem right? I am hoping that the back right is so poor that it is causing it to lock up because the back left is having to do all the work also the front right disc brake is a little poor. The fronts have never locked up. Possibly someones fitted a different sized cylinder on one rear side only? Is it best to change both rear cylinders as a start and if so where would be the best place to go about getting some? I have no idea what I need. Thanks.

You are wise to suspect unequal cylinder sizes. I had an '80 V6 Camaro years ago, discs up front but no power assist, is yours like this? Best to first pull the drums and check for leakage, contaminated linings can also give the symptoms you describe. Also allows you to check bore sizes. Replacements (if needed) can probably be sourced from the usual places (US Automotive, WASP etc) Smaller rear cylinders (if available) will reduce rear pressure and help stop locking, but maybe you need to fit an adjustable proportioning valve to gain control. Are you sure the fronts are working as well as they could be? The brakes on my '80 were good (stock) HTH
Cheers, Martin

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Yeah this is also a 1980 v6. The rears have both been leaking. I cleaned everything right up but could definitely do with new cylinders. I had the brakes tested today and although I cant remember the numbers but the back right was pathetic, the back left was alright, the front right wasn't brilliant and the front left was perfect. Though I am pretty sure the 2 brake lines do front together and back together. Front pistons both move fine and discs and pads are good too so how could one side be worse? Also do you mean one of those weight compensating valves or..?

My knowledge is nothing compared to what Martin can offer, so i'll let you guys carry on but thought i'd chime in as i've just finished rebuilding the rear drums on my '79.

First thing i'd say is about the cable the goes under the car and splits in 2. This is for the parking brake only, so only works when you put your foot down on the parking brake. You can jack the car up, start the car, put it in drive and then when you apply the parking brake, see what happens. If you have rear drums, i wrote an express run through below, so once you've done all that, come back and then you can adjust the parking brake if needs be, by turning the nut by the divider (if the parking brake isn't putting enough pressure down, once you know the system is all good).

Next thing is about the foot to the floor thing... sounds like the system could use a bleed (once the rear problem is fixed of course). Do you know how to bleed a system? A few good youtube vids about it, in a nutshell you open a bleeder, have a friend squeeze brakes slowly and then close the bleeder and move around the system until it's all gone.

Next one is more of a question... do you have drums or discs on the rear?
If it's drums, then read on, if not, ignore the rest

If it's drums, then jack the car up, take the wheels off and pull the drum off. Should come off with a bit of a tug. First thing to check is the brake shoes - are they worn? I have a feeling that one side has worn more than the other. The solution is of course new shoes. Let's say that the the shoes are all about the same thickness, then there is a way to balance the rears within themselves (you are correct - one brake fluid line for the front, one for the back). At the bottom of the drum brake assembly, there is a little bullet looking device, with teeth on it. You can rotate this so that it moves the shoes farther out or more inwards. What you would do is on the side that isn't braking enough (provided that there is still meat on the shoes and they aren't completely worn) is turn the cog a bit, try reinstall the drum, if it goes on easily, it's probably not far enough, so keep turning until you feel a bit of resistance when putting the drum on. All of that, is assuming that the drums and shoes are all good and just need a bit of a tune. Once you do that, bleed the system and you could be all good. But of course, could be more complex, that's just a starting point.

I can do you a run through video tomorrow if you need?

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Here's my brake knowlege and advice, I hope it helps:

Assuming things are as they were originally, there are two lines out of the MC, one for front, one for rear. They both go into a combination valve which controls balance and also works a warning switch if front or rear fail. From there there is a single line to the rear (runs down drivers side to the axle), where it splits via a tee to left and right. There are two lines out of the combo valve for the front, one left one right, which go directly to the calipers. There is a pin in the combo valve (sticks out of the end towards the engine) that will move if there is a drop in pressure front or rear. When bleeding you need to wedge something against this pin to stop it moving and allow the fluid to flow.


If the rear brake cylinders have leaked then I would replace them as a matching pair and also get new shoes (the old ones may be contaminated). Whilst you are at it, I'd get at least a spring kit as they can be obtained very cheaply. If you've got the cash to spare, I'd replace as many parts as possible, as what's there is 35 years old now.

The fronts is not so clear cut. It might be mis-matched calipers (these should be replaced in pairs, but you may have one side newer than the other), it might be sticky calipers, blocked pipes or something else. If it were me, the first thing I would do is completely flush the old fluid out with new (which gives you a good bleed at the same time). I would pull the caliper off the hub and push out the piston (not too far or it may fall out) to check it's movement, but also give it a good clean. You could also apply red rubber grease to protect it. Check the pad movement, make sure they are moveing smoothly and not binding. Check for even wear across the pad, and between pads. Any discrepancy may help you find the problem.

If that doesn't work, I'd replace the calipers and pads. I'd recommend you get some decent bleed nipples, as the ones that come with the new calipers are like cheese. I recommend the Hawk HPS pads, they really do work well.

I'd recommend RockAuto.com for all of these parts, as you will have more choice and it will probably be cheaper.

Thanks for the help guys. I will get 2 new rear cylinders and a full set of shoes on then bleed the system and balance the rear then set the handbrake up nicely and see how that goes.