My 60 has an issue with the rear brakes locking up , mostly in a panic situation, I've completly rebuilt all the rear brakes with OEM parts including the drums and did the fronts with new discs and pads , there is no pedal fade but something isn't rite, someone told me it was the brake perportioning valve but the '81 model did not come with one.
How can we tell when the brake calipers are shot?
- Thread starter RHON
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soundsl like you may have the wrong size rear brake cylinders on there, or maybe the rear brakes are adjusted up too far.....
Jack up the front and have an assistant step on the brake pedal as you spin each front tire. If the calipers are dragging, or not having any effect, then you've clearly got a problem. You could bleed them to check the color of the brake fluid, and for leaks.
I would bleed the whole system again and start there. Start with the rear farthest from the master looking at the brake lines. Think it is the drivers rear. Also the rears are adjusted use the parking brake. A couple of times up and down on the parking brake should set the rears.
there should be one. you may not have the rear load sensing proportioning valve, but you should have one at the master cylinder/booster unless you have a non us 4w drum spec rig.
- Thread starter
- #6
Jacked up the front end this afternoon, no noticable dragging and the the brakes seem to grab pretty well when applied, still I'm getting way too much braking in the rear.
Yes looks like there is something directly under the master cylinder-though i don't understand how it could be load sensing mounted under the hood- any thoughts on checking this for problems ?, as far as adjusting goes they seem to be rite on the money, as per the FSM , and the system has ben bled twice , yet the color of the fluid is a dark brown- my brother mentioned that it should be flushed and replaced, the whole system has been replaced except for the booster, brake lines and calipers, the dark fluid color i'm told is from the old seals ,hoses and cylanders and needs to be flushed out some how... anyway what started all this was the fact that the rear drums were very distorted telling me there was a problem back before it was torn into.
Thanks for the input, What do you suppose would be the best method of flushing out the brake lines?- (please don't mention taking it to a mechanic).
Yes looks like there is something directly under the master cylinder-though i don't understand how it could be load sensing mounted under the hood- any thoughts on checking this for problems ?, as far as adjusting goes they seem to be rite on the money, as per the FSM , and the system has ben bled twice , yet the color of the fluid is a dark brown- my brother mentioned that it should be flushed and replaced, the whole system has been replaced except for the booster, brake lines and calipers, the dark fluid color i'm told is from the old seals ,hoses and cylanders and needs to be flushed out some how... anyway what started all this was the fact that the rear drums were very distorted telling me there was a problem back before it was torn into.
Thanks for the input, What do you suppose would be the best method of flushing out the brake lines?- (please don't mention taking it to a mechanic).
There are two types of proportoning valve, load sensing usually fitted to 75 series utes/tray backs here in Aust, or the basic valve mounted under the booster. There is no way to tell if the vavle mounted under the booster is stuffed other than taking it to a brake specialist, or, replacing all of the braking system and finding out that the rears lock before the fronts as in your situation. 
The other disappointing issue is that they are not repairable, it will have to be replaced. x 2.
Another matter of concern is the colour of your brake fluid: if all the brakes components have been replaced (master cylinder, calipers rebuilt etc, and the system bled, you should have nice clean fluid, not dirty brown crap.
I would suggest:
1. get a new or good second hand proportioning valve.
2. bleed the whole system starting at the furthest brake, (passenger rear) and work your way to the closest till you have clean fluid coming out.
3. Dont try and save on brake issues, it can end up costing you a lot more if they fail.
If you can post a picture of the proportioning valve, I can compare it with the valves fitted here in Australia. If it is the same I might be able to organize one to be sent over to you if you cant locate a valve in the states.
MB
The other disappointing issue is that they are not repairable, it will have to be replaced. x 2.Another matter of concern is the colour of your brake fluid: if all the brakes components have been replaced (master cylinder, calipers rebuilt etc, and the system bled, you should have nice clean fluid, not dirty brown crap.
I would suggest:
1. get a new or good second hand proportioning valve.
2. bleed the whole system starting at the furthest brake, (passenger rear) and work your way to the closest till you have clean fluid coming out.
3. Dont try and save on brake issues, it can end up costing you a lot more if they fail.
If you can post a picture of the proportioning valve, I can compare it with the valves fitted here in Australia. If it is the same I might be able to organize one to be sent over to you if you cant locate a valve in the states.
MB
- Thread starter
- #8
Thanks for the offer , I found one at Specter off road for (used), $65.00 ,new OEM $335. ouch, let me give that a shot,
Thanks again.
Thanks again.
The proportioning valve on the booster is not load sensing. you probably don't have a load sensing proportioning valve. if you did, it would be mounted by the rear diff, with a rod to it.
Interesting! I've been having the same problem. Gone through everything. I was also thinking it was the proportioning valve. Was going to replace it with an adjustable one (cheaper than original and only takes some "fiddling" to get set right.) I'm interested to hear how it turns out.
There are two types of proportoning valve, load sensing usually fitted to 75 series utes/tray backs here in Aust, or the basic valve mounted under the booster. There is no way to tell if the vavle mounted under the booster is stuffed other than taking it to a brake specialist, or, replacing all of the braking system and finding out that the rears lock before the fronts as in your situation.
Another matter of concern is the colour of your brake fluid: if all the brakes components have been replaced (master cylinder, calipers rebuilt etc, and the system bled, you should have nice clean fluid, not dirty brown crap.
I would suggest:
1. get a new or good second hand proportioning valve.
2. bleed the whole system starting at the furthest brake, (passenger rear) and work your way to the closest till you have clean fluid coming out.
3. Dont try and save on brake issues, it can end up costing you a lot more if they fail.
If you can post a picture of the proportioning valve, I can compare it with the valves fitted here in Australia. If it is the same I might be able to organize one to be sent over to you if you cant locate a valve in the states.
MB
Bleed order for US (Left Hand Drive ) is driver rear, Pass rear, Driver front, Pass front. Note the above post is Aust. (Right Hand Drive)
Dynosoar
Correct me if I'm wrong (I'd crawl under my BJ42 right now but it's raining) but would not a Right hand drive and left hand drive have the pumpkin on the same side, meaning the brake line would come down the same place? Meaning the Aussie way would be the way. I'll check which is the longest line on the rear when it stops raining.
Cheers
Cheers
