First question, for the '87

Anyone who has seen the rear disc brake recall parts, are they or aren't they different somehow than the original parts ?

Or are they just new parts ? The original factory units worked better when new.

If they are different did they fix or help our problem ????

Second question, for the '89

GM changed our combo/proportioning valve mid year '89, I heard they changed the threads, any other internal changes made ?

Have an early '89 with the rear brake problem and have heard most '89 don't have this problem but have talked to several that do and they are EARLY '89 cars.

This makes me think GM changed the valve internally in mid year '89. If anyone has any info on this this would help out many of us with bad rear brakes, might have to cut a few brakes lines and reflare them but at least no modding the valve or adding an aftermarket one or etc. Why did GM change the thread size otherwise it would bolt up ?

I would like to swap to mid '89 up valve to find out but don't want to do all the cutting , flaring and spending 100 bucks if it is for nothing ????????????

Any info on this could help many of us, THANKS


Bill E.

 

This is not a direct answer to the question; but I can tell you that I have a 83 car, originally equipped with drum brakes, into which I put a 91 or 92 disk brake rear.

I did not change either the master cyl or the prop valve. Both are the stock 83 stuff (except that I had to replace the PV once in about 88 or so, because it developed a leak). All I did when I put the newer rear in, was to cut off the last 6" or so of the rear hard line, right before it meets the flex line; cut off the same length of the donor car; and used a flare union to put the short piece of bubble flare metric line onto the end of the SAE line the car came with.

The rear brakes work fine. The car stops much better than it did with drums so they're clearly doing more work than the drums did. The rear pads wear at about 2/3 the rate of the front pads, so they're definitely doing their job. I've had this rear in the car for about 35,000 miles; I put new pads in it when I put it in, and I had to change them about 2,000 miles ago. Fronts last about 20,000 miles. So it seems like it's fairly well balanced to me, just from casual observation.

 

Jack up the rear tires and see if you can turn them. I am betting they are dragging.

 

Anybody ?

 

Did you do what I said and see if they are dragging?

 

Dragging , if they were I would have pretty good rear brakes, problem is most who have this problem is the brake pads are TOO FAR from the rotor not to close............

Bill E.

 

Sorry, I got you confused with RB83L69.

 

I installed the recal kit on my car. I don't have the part #, but i found on a thread here. You may be able to find it if you do search.

The parts looked the same to me. The only difference was the the new pistons didn't have a rubber grommet in the center. I don't know what is was for on the old piston, but it didn't seem like it had any purpose to me.

It did make an improvement in braking, but didn't help the low pedal problem. My rear brakes wouldn't even knock all of the rust off of the rotor, and the e-brake didn't work. Now I have nice shiny rotors and an e-brake that works.

 

Did the search for you:

GM part # 18019028

 

83 drum MC & PV = 91-92 disk MC & PV

Can't see where they would have suddenly taken a left turn down a dirt road with that in early 89 and then suddenly re-found the true path later in the year, but I'm no expert on such things.

No rust on my rear calipers. No dragging either, if you're asking me about that; as far as I can tell they work perfectly.

My comments were directed toward/about the 89 thing. I have no info about the 87. Everybody knows the Saginaw calipers were a terrible system, I've avoided those like the plague, so I can't tell you anything about them except that if you have them you should consider getting the better ones. It was pretty common knowledge that they were crap shortly after the 84 model year cars came out with the new MC & PV, and their rear disks didn't work any better than their predecessors.

 

The kit was installed on my 85 several years ago. I've never experienced any problems whatsoever.

JamesC

 

Hmm.. I was sitting on some ice the other day at a stop sign(89 Formula), and i could feel my back tires still turning. I put the car on a hoist, and sure enough my rear rotors were rusty!!!

I wonder if I have the same problem

 

They are completely different. The piston "loosk" abot the same but the internals in it are different and the springs for them are different.
Fixed the problem for me. I now have a fully functional parking brake and much shorter stopping distance.

 

To all you guys running the "old" iron rear calipers. I can't stress enough how much better the '89-97 PBR rear brakes are. I know you can install the recall kit in your present calipers but you'd be better off (IMO) to swap to the newer style. Easier to maintain, won't rust away on you, and you also get a larger rotor which gives you more braking force. It's not a hard swap to do and all the parts are easily available.

Just my 2 cent.


Ed

 

$35 is a whole lot cheaper than a new brake setup. Some of us don't have large amounts of money to spend.

 

Mine do the same ****.

 

86, I'm just giving my opinion here. If you're on a budget, then do the recall kit obviously. But if you know where to look, you can upgrade to PBRs for less than $200. I know of a complete upgrade kit out there for @ $500 that includes everything you'd need to swap over and it's all new parts. For comparison, Baer charges $795 for that same kit.

Ed

 

I just called on rotors and calipers from a place I typically get a good deal on parts. The rotor is $36 and the calipers is $85, thats one side without pads

Looking like $350 to do it myself...ouch I also probably need to do the fronts also since they have been stopping the car for who knows how long.

What does PBR stand for? aluminum?

 

PBR is the company (Australian) that made them. THey have that name cast into them.