95 K2500 SUBURBAN ABS BLEEDING ?

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bugdewde

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1995 K2500 ... OBD1 ... no scanner

I'm replacing my front brake calipers, hoses, unit bearings, idler, pitman, etc .....
I've owned this rig for almost 4 years (15k miles) and the brakes have SUCKED since buying it. I mostly only use it to tow my car trailer which is the only way it stops ok (trailer brakes, lol).
ABS light has been on since I bought it.
I've run the ABS codes when I bought it 4 years ago and have gotten a 21 & 22. Both Right Front codes.
I can feel the ABS pulse under hard braking....
The thing is ..... it appears only the right front brake has been working most all this time. Yes, it has pulled to the right under hard braking all this time.... but trailer brakes made it usable for me lol.
When backing up to my car trailer in gravel, during high idle when cold, the right front locks up and slides .... tearing up grass, dirt and gravel.
Well, Right Front went metal to metal on my last 300 mile tow job (hence the reason for the replacement job) ... See pic.
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ASSUMING, the bad ABS sensor code on right front is allowing the RF to lock up and actually work .....
OR .... the rest of the system isn't working for crap (bad ABS unit?). I have no idea.

So .... recap:
1. Brakes have sucked, with codes, for almost 4 years (I'm lazy & use trailer brakes).
2. Rear shoes have been adjusted 5 or 6 times over the years ... but shoes show minimal wear... assuming not getting a lot of pressure back there ... wheel cylinders not leaking. Parking brake works well when adjusted.
3. The right front has ABS codes but seems to be the only brake working well. The new bearings have new ABS sensors, when installed.
4. When I get all the hydraulics installed and attempt to bleed the system, WITHOUT A MULTI-HUNDRED DOLLAR SCAN TOOL, ....
what tips, issues, suggestions, advice can I get from you guys?
5. I remember reading something about the gravel stop method for actuating the ABS solenoids/pump a few years ago. Is that really effective?

1995 ... OBD1 ... assuming its the EBC-310 ABS unit. Don't know how to tell the difference.

How do I get this system back to working without the high dollar scan tool? Don't want to rely on trailer brakes any more (time to address their wear, too ... lol).
 

HotWheelsBurban

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1995 K2500 ... OBD1 ... no scanner

I'm replacing my front brake calipers, hoses, unit bearings, idler, pitman, etc .....
I've owned this rig for almost 4 years (15k miles) and the brakes have SUCKED since buying it. I mostly only use it to tow my car trailer which is the only way it stops ok (trailer brakes, lol).
ABS light has been on since I bought it.
I've run the ABS codes when I bought it 4 years ago and have gotten a 21 & 22. Both Right Front codes.
I can feel the ABS pulse under hard braking....
The thing is ..... it appears only the right front brake has been working most all this time. Yes, it has pulled to the right under hard braking all this time.... but trailer brakes made it usable for me lol.
When backing up to my car trailer in gravel, during high idle when cold, the right front locks up and slides .... tearing up grass, dirt and gravel.
Well, Right Front went metal to metal on my last 300 mile tow job (hence the reason for the replacement job) ... See pic.
You must be registered for see images attach

ASSUMING, the bad ABS sensor code on right front is allowing the RF to lock up and actually work .....
OR .... the rest of the system isn't working for crap (bad ABS unit?). I have no idea.

So .... recap:
1. Brakes have sucked, with codes, for almost 4 years (I'm lazy & use trailer brakes).
2. Rear shoes have been adjusted 5 or 6 times over the years ... but shoes show minimal wear... assuming not getting a lot of pressure back there ... wheel cylinders not leaking. Parking brake works well when adjusted.
3. The right front has ABS codes but seems to be the only brake working well. The new bearings have new ABS sensors, when installed.
4. When I get all the hydraulics installed and attempt to bleed the system, WITHOUT A MULTI-HUNDRED DOLLAR SCAN TOOL, ....
what tips, issues, suggestions, advice can I get from you guys?
5. I remember reading something about the gravel stop method for actuating the ABS solenoids/pump a few years ago. Is that really effective?

1995 ... OBD1 ... assuming its the EBC-310 ABS unit. Don't know how to tell the difference.

How do I get this system back to working without the high dollar scan tool? Don't want to rely on trailer brakes any more (time to address their wear, too ... lol).
You might have a collapsed hose or sticking caliper piston, to make the front brakes be like that on only one side. I'm not ruling out a problem with the ABS system, but I have seen this problem also be caused by a bad hose or caliper. If you think the hoses are original, I would recommend replacing them.
 

bugdewde

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You might have a collapsed hose or sticking caliper piston, to make the front brakes be like that on only one side. I'm not ruling out a problem with the ABS system, but I have seen this problem also be caused by a bad hose or caliper. If you think the hoses are original, I would recommend replacing them.
Yes, I'm replacing the soft hoses and the calipers.
Suburban is at my buddy's place about 30 miles away. Once we get all the new stuff installed, I'm pessimistic about the brakes magically working as they should.
Since the ABS is the only thing not getting replaced, I assume the worse... that the ABS will need bled or replaced/by-passed.

Is there a way to activate the later ABS solenoids/pump OTHER than the gravel road or scanner method?
I'm just trying to get as much info on the ABS stuff BEFORE we bleed the calipers/cylinders... assuming I'll have to address it.
Thanks for the reply. Fingers crossed its only the hose or caliper.
 

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Schurkey

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You have a 3-channel ABS unit. When you go slidin' on gravel, how do you know you're activating all three channels?

I suppose it's possible to activate ALL of the ABS by slidin' on gravel, but it's not a sure thing, and then you have to bleed the brakes at the wheels to get the air out of the system HOPEFULLY before it goes back into the ABS unit.

Short Story: You need a scan tool to chatter the ABS unit in the shop, so you can bleed the wheels promptly afterward. Which maybe means you need to find and pay a shop to do this since you don't want to buy a scan tool. Instructions attached.
 

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offroadtahoe

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if your replacing calipers upgrade to the 1ton dually calipers/disc/pads.you can also use the dually rear brake cylinder

also here is a video on bleeding the abs without scanner
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Schurkey

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also here is a video on bleeding the abs without scanner
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Wrong ABS unit. That's the older EBC4, not the EBC310.

And don't be fooled. He's still not bleeding the ENTIRE ABS unit, just the "easy parts". The accumulators are not getting bled with his method.
 

bugdewde

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bugdewde

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New calipers, rotors and hoses are installed. We gravity bled them a bit and then manually bled them. Doing the burn in, or seating of the pads, they seem to be a lot better now. No pulling to the right anymore .
Pedal seems a bit spongy with some travel .... but its been soooooo long ago that I've had good brakes on a 400, I don't remember how its supposed to feel.
- - By the way, the ABS light is now out!!! Yippee !!!!
We did the gravel road "test" (didn't bleed afterwards) and the pedal pulsed and we could hear the pump running (quite loud). ABS light stayed out. Yippee, again!

New loaded lower control arms, front shocks and unit (hub) bearings installed as well...
Still have to change out the idlers (lots of slop there). I have parts on hand. Anxious to get the old burb rollin' again!

I added myself to the community scan tool request .... fingers crossed.
Thanks for your replies and help.
 

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bugdewde

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All done..... bled it a few times and its greatly improved. Activating the solenoids would probably make it even better.
One issue was the steering damper taper didn't match ..... so my buddy just cut it and drilled and tapped it to accept the bolt.
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