Hey guys. I have an 83' Trans Am with the stock cast iron Delco rear brake calipers. The calipers are in poor shape (need replacement/rebuilt). At this time I am wondering what are my choices for upgrades that will directly bolt on or should I stick to the stock Delco's? I don't want to spend alot, but perhaps there is an upgrade that bolts on? I see tons of drum to disc conversion kits offered online.........but what about the folks who are running stock rear disc setups and just want a better caliper? choices?........

 

Not really anything that both

and

Those calipers are CHEEEEP as such things go. Just replace em; install the "recall kit" in em; and look into the proportioning valve mod that's been discussed on this forum.

 

Yeah, I think I will just replace them with new units from the auto parts store. They sell for $58 per caliper. Not too bad. Do the new calipers come standard with the upgraded "recall kit" or do I need to find and install those parts myself? Thanks

 

My only complaint about them is they use that stupid turning cylinder. I wish they would just compress like a normal caliper.

What was the recall kit again? I vaguely remember this.

-- Joe

 

GM 18019028. Recall info below:

http://members.shaw.ca/crussel/recalls/86c28/86c28.html

JamesC

 

I'm swapping the Delco to PBR on a 9 bolt. You need the mounting brackets, caliper and caliper brackets, rotors and pads and reroute/cut/reflare one of the brake lines. Pretty much. I got the whole lot for $100. Not all shiny but functional. If you don't want to spend much just get reman Delco but be on the look out for a great deal.

 

I learned the hard way........... tonight I decided to investigate the inside of the piston. I took apart the caliper piston arm and out popped the whole piston! I now understand what the "helical" design is all about. One big question: "How the heck do you reinstall the piston back into the bore while its under spring tension and must spiral back onto the helical"? This looks like a royal PITA to get the piston back into the bore and also get the rubber dust seal to expand around it. I fought with it quite a bit. Special tools........extreme patience......... whats the trick?

 

So that was only up to '86? So 87-88 cars were fine?

-- Joe

 

Just wondering..........are the brass "banjo" rear caliper brake line fittings a special metric flare or just the standard SAE brake flare?

 

The calipers look like the fronts with a park brake added. Could you just use a pair of fronts and sacrifice having a parking brake?

 

They're not the same. Front is two piston I think rear is single plus the rotors are different sizes.

 

No the fronts are not two piston.


Yes the calipers are the same, minus the parking brake.

Its the standard GM "Metric" caliper, also used on G bodies and s series pickups for much of the 1980's.

 

BOTH calipers are not the same. The fronts are dedicated right/left. The rears are the same caliper mounted opposite side to side (so the bleeder is up).

 

So which one matches the rears? Front left or front right?

 

Neither would work for the rear. The pistons size of the front caliper is WAY to large. You would have way to much rear brake. This is not a good idea in any way.

 

Many circle track guys use them, Speedway even sells many brackets and kits.

Might be a little different in that application though.

 

There are a lot of different kinds of circle track racing, please specify so I can respond intelligently.

When they use these front calipers on the rear, what are they using on the front?

How are they modulating front to rear pressure? Are you planning to do the same?

Are you building a circle track car?

 

I don't know.

No I am not building a circle track car. Just recall seeing the stuff offered in the Speedway catolog.

No I am not planning on installing front calipers on my rear.

 

Has anyone experienced brake fitting sealing issues on the rear cast iron Delco Calipers? On the cast iron calipers themselves, there are small raised circular patterns machined into the brake fitting face so the copper washer can seal. What happens when these small circular patterns fade away over time and the copper washer no longer seals? Is there an alternative way? I have turned in my old calipers for rebuilt/reman units and found that every reman unit seems to have no raised circular patterns left for sealing. I have returned the calipers back to the auto parts stores multiple times in hopes of getting a better unit that has the raised circular sealing patterns. No luck and running out of options! The darn thing will not seal without them. Can a good machine shop fix this?

 

Lots of modern calipers come with flat sealing surfaces. I can't imagine yours have just worn away. How tight are you torquing banjo bolt?

 

or the brake line is being installed with the wrong face towards the caliper?

 

Ok folks, here are some pictures of what I am up against for sealing. The new cast iron Delco caliper has very slight raised circular edges (barely can catch my fingernail on it). The brass "banjo block" has nice raised circular edges (phonographic finish) that bite into the copper washers on both sides. I am happy with this part............but the caliper itself seems to have poor raised edges for sealing. Anyone else have a sealing issue or believe this caliper is considered "good"? I'm stumped on this..........

 

If its flat it should be fine. Lots of calipers have ungrooved seats. Again, how tight are you making the banjo?

 

I am sure the banjo bolt has a specific OEM torque........basically I am tightening it "mechanic snug". I understand that these bolts are hollow in the middle and are suseptable to "stretching" severly if overtightened. Is there a certain torque value/method of tightening for it?

 

I don't know what mechanic snug means. That could meaning anything depending on the length of the tool used.

It should be in the neighborhood of 17 ft-lbs. Use NEW crush washers.

Remember, for a banjo arrangement you are troquing for crush washer sealing, not for bolt stretch. As a result, the torque spec is much lower than for the bolt itself.

 

Ensure the brake line fitting is flat on the face when it meets the caliper. One side is specific to the bolt.

 

So I just measured the pistons on my rear calipers and they are 1 3/4" Which from what I have seen is the same as the fronts.

 

I am not sure what you mean when you say "what I have seen". I think if you measure one you will find that the piston is 2.5" diameter.

The area of the front caliper is 4.91 in^2 whereas the rear is 2.81 in^2. Quite a difference.

John