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Brakes 1996 K1500 Suburban What are good local options?

J

jrsavoie

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The brake pedal is spongy on the 1996 K1500 6.5 diesel GMC Suburban.

The rear brakes have about 50,000 miles. The Suburban has about 355,000 miles

I had the master cylinder changed twice and got screwed twice. It was supposed to get an AC Delco and both times it got a NAPA.

The last time it was changed was about 4 years and 20 or 30,000 miles ago

I know I should know all this, but I do not remember much.

What are the options for rear and front brakes on these? It seems to me that you could get something different than what the vehicle calls for and get bigger pads or something.

Seems to me you would be stuck with few choices / options on the rear.

What would be the best parts available?

What would be the best parts available that we could get today? Napa, Autozone, Oreilly's, Advanced, Fisher are local parts stores

What is the fastest way to determine if the master cylinder is good or bad?

The more I think about it, it is acting like it did the last 2 times the master cylinder was changed.

I need to get done ASAP. I still have the work bay in my shop blocked, so I am messing around working behind that.

I plan on starting by pulling a rear wheel off and seeing what I have there
 
I'd start by bleeding them. A good way to do it is use your finger in put it over the bleed screw have someone slowly pump the brake pedal while your finger is firmly against the bleed screw. Acts like a speed bleeder. Does a better job than any other method I've tried. Oh and use a rubber glove. If brakes are still spongy than look at the MS.
 
1/2 ton GM brakes for this era were overheated mush. Stand on the brakes: does the pedal sink? If so there is a leak. Master cylinders leak internally so check everywhere else for an external leak incl wheel cylinders. Look in the reservoir for a bunch of black debris from the MC seals.

To get rid of the mush feel you start with a brake system flush to get the moisture out. How well does the MC cap and rubber part fit? It can let a lot of moisture in if it doesn't fit perfect. Tighten the rear adjusters - every other oil change. Then SS braided brake hoses. And I understand it the final mush fix is dual piston calipers because a lot of the mush is the front calipers flexing. (Never did this upgrade.)

Or get a Dodge with 4 wheel disc. :p
 
Big T said:
Go yard: GMT 800 upgrade.

http://www.thetruckstop.us/forum/threads/gmt-800-brake-conversion-silverado-hd-2500.45047/
Click to expand...
' have been wanting to do that upgrade for a long time. I don't know that I put enough miles on anymore to justify spending the time.

What does it take to go from 2 1/2" shoes to 3 1/2" ? I have 13" drums.

The drums are the same depth.


There was air in the lines of the front brakes. Had to replace the right front caliper because the last POS that worked on the Suburban never used anti-sieze on the bleeder screw.

Back brakes were not properly installed - 13" x 2 1/2" wide shoes. Getting new shoes from Advanced today. I found 3 1/2" Shoes and drums yesterday. Could not get 2 1/2" then.

Looks to me like all you should have to do is replace the mounting plates to change from 2 1/2" to 3 1/2" shoes and drums
 
Should have bought the brake gear I had for sale.

Now that I've got the "stuck in 4wd" issue solved, I can focus on the results of the GMT 800 brake conversion. The results are great. Can't wait to see what the results are with the GMT 800 14 bolt FF axle with disc brakes. The axle purchase and conversion was actually cheaper than new drums and shoes.
 
Big T said:
Should have bought the brake gear I had for sale.

Now that I've got the "stuck in 4wd" issue solved, I can focus on the results of the GMT 800 brake conversion. The results are great. Can't wait to see what the results are with the GMT 800 14 bolt FF axle with disc brakes. The axle purchase and conversion was actually cheaper than new drums and shoes.
Click to expand...


Shoulda, woulda, coulda - Didn’t happen


I don't remember what came up then, I certainly wish I would have too.

IS it possible to change the backer plate and use the 3 1/2" shoes and drums? I will have to revisit your threads when I have time.

Worked on the 1996 K1500 6.5 diesel Suburban with 355,000 miles this weekend. Never had much for internet service all weekend which Kind of makes it a PIA anymore.

The rear brakes had about 50,000 miles on them and the front brakes only had about 10,000 miles on them


One of the adjuster plugs was missing and it was pretty corroded - Just another reason why I hate taking things to people - at least if I screw up it's on me - but it doesn't seem like that happens near as often as when I take things to people. There was also a few missing parts on the back. A Couple of E clips and something else. The same place also installed the Napa Master cylinder when they had agreed to only install an AC Delco.

The first Master cylinder lasted a long time. I do not remember ever changing the master cylinder before 270,000 miles - I think it was. I took it to a shop that time also - He installed a NAPA master cylinder Then At about 300,000 miles the master cylinder was replaced again -

I remember why I did not work on the Suburban that time. My truck had the Christmas issue at the same time and I was trying to find, what ended up being, a pin not making connection in the IP harness


Found out that rear wheel cylinders, do not come with the cylinder to brake shoe links from parts stores anymore.


First time I ran into that.


Also found that nobody carries the little rubber caps for the brake bleeders or the inspection hole / adjuster plugs


And the brake spring kit does not include the adjuster. I had told them that I wanted everything for both sides. So I should not have had to go back for the adjusters or the links anyway.

There was a little air in the front brakes when we bled them - rotors, calipers and pads looked good. Had to change the right caliper because the last person to work on the suburban did not do as I told them to and anti-seize the threads on the bleeder. It broke rather easily.

The back brakes and drums were in good condition and looked like they could go another 150,000 miles.

Except that the shoes were cracked. We went ahead and installed all new parts.

Right rear line twisted when we were removing the wheel cylinder. We replaced that with some of the nickle line - I always say new style line because I never used it before, but I think it's been out for a long time now.

The time saved ordering stainless lines from inlinetube.com has been worth it to me.

End result is the braking feels better, but is still spongy. There does not seem to be any anti-lock action going on.

Any further Advice or things to check?

What is the best master cylinder to buy? = if that ends up being the issue
 
WarWagon said:
1/2 ton GM brakes for this era were overheated mush. Stand on the brakes: does the pedal sink? If so there is a leak. Master cylinders leak internally so check everywhere else for an external leak incl wheel cylinders. Look in the reservoir for a bunch of black debris from the MC seals.

To get rid of the mush feel you start with a brake system flush to get the moisture out. How well does the MC cap and rubber part fit? It can let a lot of moisture in if it doesn't fit perfect. Tighten the rear adjusters - every other oil change. Then SS braided brake hoses. And I understand it the final mush fix is dual piston calipers because a lot of the mush is the front calipers flexing. (Never did this upgrade.)

Or get a Dodge with 4 wheel disc. :p
Click to expand...

The cap on the Master cylinder fits very tight. So tight that it is a PIA to get off.. The rear brakes were adjusted correctly - but the shoes were cracked.

The fluid was lightly discolored.

By the time we were done yesterday, we had gone through 2 quarts of brake fluid.

The reservoir was never allowed to get empty.
 
jrsavoie said:
The cap on the Master cylinder fits very tight. So tight that it is a PIA to get off.. The rear brakes were adjusted correctly - but the shoes were cracked.

The fluid was lightly discolored.

By the time we were done yesterday, we had gone through 2 quarts of brake fluid.

The reservoir was never allowed to get empty.
Click to expand...

The rear brakes have more clips and springs than a Swiss watch. That is why I’m moving towards the GMT 800 axle with disc brakes.

The P.O. of my truck gave me a box of parts when I bought it and in there was a master cylinder. I installed that when I did the GMT 800 brake conversion. I don’t think you will ever get a brake pedal that feels as hard as a rock on these trucks, but spongy is not ideal nor acceptable.
 
GMT 400's are pretty much all, I, or the friend that was helping, have ever owned. - at least since 1989 - LOL

We should have an idea of what the brakes are supposed to feel like. Not to say that we can really tell anything about anything, anymore. You hear a lot of "What?" when we are around.
 
@jrsavoie at the risk of doing the job over: what did you use for rear shoes? If they didn't cost near $100.00 then IMO they are garbage. Parts stores are in a race to the bottom and have punched through the bottom of the barrel for cheap fix and flip rather than good long lasting parts. I remind you of the time I had a duracrap Autozone pad come off the backing plate and quick couple pumps of the INOP brakes later (while considering flooring the e-brake) trashed the rotor after the brakes recovered. Wagner ThermoQuiet stops quicker than the best duracrap pads sold period. I put a lot of these on vehicles for side jobs and they work very well. Raybestos also has a good product.

I found the rear shoe material makes a difference in stopping distance esp. when towing. @Big T has absolutely gone further with improvements.

This said a set of pads and shoes from Wagner or Raybestos should stop better than the top of the line store brand. Yes, you can do worse than stock! I favor the semi-metallic over ceramic as I don't care about dust and IMO semi-metallic stops better.
 
WarWagon said:
@jrsavoie at the risk of doing the job over: what did you use for rear shoes? If they didn't cost near $100.00 then IMO they are garbage. Parts stores are in a race to the bottom and have punched through the bottom of the barrel for cheap fix and flip rather than good long lasting parts. I remind you of the time I had a duracrap Autozone pad come off the backing plate and quick couple pumps of the INOP brakes later (while considering flooring the e-brake) trashed the rotor after the brakes recovered. Wagner ThermoQuiet stops quicker than the best duracrap pads sold period. I put a lot of these on vehicles for side jobs and they work very well. Raybestos also has a good product.

I found the rear shoe material makes a difference in stopping distance esp. when towing. @Big T has absolutely gone further with improvements.

This said a set of pads and shoes from Wagner or Raybestos should stop better than the top of the line store brand. Yes, you can do worse than stock! I favor the semi-metallic over ceramic as I don't care about dust and IMO semi-metallic stops better.
Click to expand...

No matter what job I am doing , I always try to seek out the best parts available.

I have never seen a cheap part save me money.

I usually search for a better part as you have recommended. Yesterday we just went with O'Reilly's store brand. I called every parts store within 45 MILE RADIOUS and all anybody had was cheap shoes.

We really needed to get it back together

I started checking Amazon and got overwhelmed with choices. Does anybody have any recommendations for a specific 13" x 2 1/2" brake shoe for the 1996 GMC K1500 Suburban?

I like Amazon or Ebay, but will order from anywhere.

I have ordered brake parts from brakeperformance.com

https://www.amazon.com/s/ref=au_pf_...296--9-9-8-4731-604-9-2--94-1&tag=jhdiesel-20

Can the brakes on this Suburban be upgraded to 3 1/2" drums and shoes by switching the Brake backing plate to one from a truck with 3 1/2" brakes?
 
Last edited:
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@RockAutoLLC has the Wagner ThermoQuiet Riveted shoes. Open mouth insert foot on the $100 price as they are $30-50 on RockAuto.

But $100 is what The Leprechaun store charged when they carried Wagner ThermoQuiet. I think they can still order them: or not on their race to deliver the same cheap house brand krap as Autozone. I do not like their house brand. *shrug* S#it's not going to run today till the mail order parts arrive. I don't waste my time on house brand brakes anymore. (No, take your side work vehicle elsewhere as I am NOT putting that krap on.)

If you don't use new drums or turn them the shoe has to wear into the drum before you get the best performance from them. The drum diameter is larger than the shoe diameter. The high spots have to wear and seat into the drum.

Bigger shoes mean a larger contact area and the larger contact area takes more force to get the same friction. Now if the shoes are fading from overheating the larger ones with more force work better and last longer.
 
Can the brakes on this Suburban be upgraded to 3 1/2" drums and shoes by switching the Brake backing plate to one from a truck with 3 1/2" brakes?

My computer has been locking up a lot. It has been pretty frustrating
 
I've been having issues bleeding the brakes on the Suburban. The biggest issue is the day I had help, the line going to left rear wheel cylinder did not get tightened 100%.

After that I only had about 5 minutes of help - somebody to push the brake pedal.

I did some searching and was told that the Mighty Vac wasn't a good tool for this vehicle and I would be better off waiting for a pedal pusher.

Did some more searching and found the Speed Bleeders. I ordered a couple of sets.

I almost took a road trip. They aren't far away. Right up by Mike.

Has anybody else used them? How did they work out? Looks pretty fool proof to me.

speedbleeder.com
 
Willwood has a good enough reputation to stray from AC Delco, but unless you are upgrading calipers to require the change I would stick with AC.
 
Will L. said:
Willwood has a good enough reputation to stray from AC Delco, but unless you are upgrading calipers to require the change I would stick with AC.
Click to expand...

What would a good caliper upgrade be?

The Advanced Auto caliper I used only lasted less than 100 miles and stuck. It popped lose with the rap of a hammer, but I can not have that happening
 
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