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Still brake problems

Rock Auto is showing two different part numbers for the 96 and 97 3500 . I would think you would need to know the brake system numbers for ordering the correct parts i.e. JB7 or JD8 etc . These are on the glovebox door with all the other codes .
 
haven’t followed the saga from the beginning so forgive me if it was already mentioned. did you replace the rubber brake lines?
 
Ok so update....we replaced the hydroboost and master cylinder.. after bench bleeding the master cylinder(assembled them on the bench to make sure they fit together correctly with the rod installed). When you pushed on the rod that the brake pedal would hook to you could actually feel the rod on the other end as it engaged the master cylinder.. like it moved maybe an eighth of an inch then hit the master cylinder (perfect).... Installed it in the truck..(and installed a new AC Delco brake light switch in the process since the generic one I had in there wasn't allowing my downshift to work correctly all the time it was kind of sporadic..) we hooked the brake lines up and took her for a run...
WOW. It felt like I got my old truck back... She went from feeling like she had 15 tons hooked up to the back of her to feeling like a NASCAR when the green flag drops.. you touch the throttle and she is gone...I will say that trucks always impressed me being a one ton dually crew cab how fast it takes off.. I guess that just must be a 6.5 thing ..
Anyhow.. we are changing the calipers rotors brake pads and brake hoses today.. the rotors are actually blue from overheating so much.. and the calipers I just put on last week are not releasing correctly even with the new hydroboost and master cylinder... They are sticking a little when you go to push them in but that's more than likely because they've gotten over heated so badly. So we figure it's all under warranty so we're going to go ahead and put everything new on since we got the hydroboost and master cylinder figured out when working correctly now.. we figure the calipers hit the hoses are rotors everything has been overheated so we don't know what damage has been done to them so why risk it...
I appreciate all the advice you guys have gave me the past few months trying to figure this problem out...
I want to just blame AutoZone for selling me the wrong master cylinder to begin with. But honestly I have a hard time doing that.. because I went in there and looked up the part on the computer. put my own information in and it pulled up the same one..so I went over to advance Auto had them look it up and it came up with the same one and the same thing happened at CarQuest...I think it's just one of those things that the computer systems just doesn't allow for when GM crossover parts... You can guarantee for now on I'm just going to go by the glove box codes once I learn what they all mean..
Maybe now I can get around to putting the other part in that the truck has been needing... Valve cover gaskets ..exhaust manifold gaskets.. few other miscellaneous parts that have been getting neglected while this saga went on..
 
MrMarty your not kidding.... I have never had this much trouble trying to figure out a problem...and it probably sounds kind of stupid but last night was the first good night I slept in I don't know how long.... Because in the back of my mind I know I'll finally be able to go back to work.... It sounds crazy but when your livelihood depends on your truck, and it's the only one you've got it's nerve-wracking as hell when you cannot get it right and you don't know how long it's going to be till you can... One thing I won't do I will not leave home with the truck to go on a run if I don't trust it at the time cuz I don't want to get stuck eight hundred or thousand miles from home...
 
Good to hear getting under control.
If you can, please post pics comparison between the different parts for others in the future. Maybe pic of rpo codes also so they understand what you are referencing.
 
Ok so update....we replaced the hydroboost and master cylinder.. after bench bleeding the master cylinder(assembled them on the bench to make sure they fit together correctly with the rod installed). When you pushed on the rod that the brake pedal would hook to you could actually feel the rod on the other end as it engaged the master cylinder.. like it moved maybe an eighth of an inch then hit the master cylinder (perfect).... Installed it in the truck..(and installed a new AC Delco brake light switch in the process since the generic one I had in there wasn't allowing my downshift to work correctly all the time it was kind of sporadic..) we hooked the brake lines up and took her for a run...
WOW. It felt like I got my old truck back... She went from feeling like she had 15 tons hooked up to the back of her to feeling like a NASCAR when the green flag drops.. you touch the throttle and she is gone...I will say that trucks always impressed me being a one ton dually crew cab how fast it takes off.. I guess that just must be a 6.5 thing ..
Anyhow.. we are changing the calipers rotors brake pads and brake hoses today.. the rotors are actually blue from overheating so much.. and the calipers I just put on last week are not releasing correctly even with the new hydroboost and master cylinder... They are sticking a little when you go to push them in but that's more than likely because they've gotten over heated so badly. So we figure it's all under warranty so we're going to go ahead and put everything new on since we got the hydroboost and master cylinder figured out when working correctly now.. we figure the calipers hit the hoses are rotors everything has been overheated so we don't know what damage has been done to them so why risk it...
I appreciate all the advice you guys have gave me the past few months trying to figure this problem out...
I want to just blame AutoZone for selling me the wrong master cylinder to begin with. But honestly I have a hard time doing that.. because I went in there and looked up the part on the computer. put my own information in and it pulled up the same one..so I went over to advance Auto had them look it up and it came up with the same one and the same thing happened at CarQuest...I think it's just one of those things that the computer systems just doesn't allow for when GM crossover parts... You can guarantee for now on I'm just going to go by the glove box codes once I learn what they all mean..
Maybe now I can get around to putting the other part in that the truck has been needing... Valve cover gaskets ..exhaust manifold gaskets.. few other miscellaneous parts that have been getting neglected while this saga went on..

Glad you got it resolved. Now do the GMT 800 front brake conversion so they never match the glove box codes.:meh:
 
The gmt what??..lol...if I have my way the next brake conversion thing on this truck will be turning the rear end to disc brakes instead of drum... Somehow I know I'm going to get yelled at for that lol
 
Untill you loose the drums adjust them every other oil change : aka 5,000 Miles. Yes, that's the HD use of 2500 mile oil changes from my 1993 owners manual.

How hot did the tires get from the brake overheat? You need to keep a close eye on them for sidewall separation by the beads.
 
That would explain why my truck destroyed a brand new set of tires..put a new set on back in December..6 brand new 235/85r16s... They were fine all winter.. but once spring hit they started blowing belts left and right.. and blowing big knots in the sides of them.... Honestly I thought it was just cuz they were junk tires... So right now I have the set on it that I had before them
 
The GMT800 is the newer style trucks. They have bigger calipers and rotors and with some mods will fit our GMT400 trucks. It would help you out with the loads that you haul if you did it.
 
Oh.. awesome!!. I figure with the disc brakes they're just easier to work on when something goes wrong..
 
I'm hoping to find a truck in the junkyard with a disc rear end

I have a Corporate 14 bolt FF axle with disc brakes prepped for install on my son's '94 Suburban. The axle is 2" wider, so you have to cut off and install new spring perches in the correct position. Same with the rubber snubber perches. Otherwise, it's relatively easy to do and I got the complete axle with brakes from a pick a part yard for like $260, which is much cheaper than some aftermarket brake conversion kit that uses calipers from a Cadillac or something like that.

I am so backlogged with projects and regular day job that this axle project has been down the list for awhile. That said, I would always do the GMT 800 conversion first as you want the stopping power in the front, else the back will want to become the front.
 
Yeah my TSM rear disc conversion came in at just under a $1000 all in, that includes a double caliper bracket and regular non caddy calipers and a separate mechanical E brake caliper. But boy am I much happier!

Cheers
Nobby
 

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