Anybody versed in Chevrolet trucks?

[hodge]

We- my dad and I- have a 99 Chevrolet 3500 dump truck. It is 4WD, has a manual transmission, a 350 V-8, and 58,000 miles on it.
We are having issues with the brakes, and it needs an ABS pump. We don't want to go the used parts route, but would prefer either a rebuilt or new pump. But, it doesn't appear that new is available anymore.
Anybody with knowledge, experience, or info on ABS pumps? I've web searched, and come up with nothing. I've joined a Chevrolet forum- 92 views at the last look, with no replies. For that matter, over 100 views in the introduction section, with no replies- not a very friendly bunch. Makes me appreciate OTT even more.
So, my expectations are low, but I thought that I might tap into someone else's experience, by chance.

This is the truck-

 

[Tooljunkie]

What sort of issue are you having with abs? Scanned for codes and symptoms?
The pumps rarely go bad, but they suffer from power/ ground issues. I havent had a lot to do with the ecbm itself,as soon as i reach the point where i need to go deeper and find a rebuilt most people choose to drive without abs.

 

[hodge]

That involves a long, sordid story. ABS is disabled, but I am still experiencing brake issues. Spongy pedal, pedal to the floor, rock hard pedal- all within 3 hours of driving. Brake fluid is leaking out of one of the valves on the ABS pump. So, simply disabling the pump and reverting to standard brakes isn't working. Something is wrong inside the replacement/used pump, so we had hoped to not try that again and go with a reman one. Therefore, I was hoping someone here might have had experience with this. I had joined a Chevrolet forum- seemed to be a good one- but with 134 views to my introduction without a single welcome or reply, and 116 views to my question without a peep- not even a moderator has stepped in and said hello or given any advice- I figured a Kubota forum was better than a cold, dead Chevrolet forum...

 

[85Hokie]

Mark,

based on what you are describing - the mushy would be air (or boiling fluid), the pedal to the floor would be that there is nothing to move fluid wise - the firm would be what it should be ? WHen it worked perfectly - the pedal was firm all the time? Could this be a master cylinder problem along with the leak from the valve at the ABS pump?

 

[bh115577]

Did you reuse the transfer tubes? Could be the cause of the leak.

 

[nzzshl]

Hodge..... because you have a leak within the ABS Module (located under the drivers seat exterior floor pan area), it will have to be replaced. Had similar symptoms with my Dad's truck in the 2500 series. replaced all of the brake lines with Stainless for about $200, a bad caliper and a couple rotors. His ABS module was crappo. Start the system bleed at the furthest bleed fitting from the reservior. Have at least 2 qts of fluid ready to rock before you crack the first fitting, 3 would be best. I personally like to remove the driver's seat from the truck and cut a rectangular hiole in the floorpan to work in that area, patching it is easy and there are no structural demands on it. Do as you may. Get the module replaced, static-bleed thoroughly and actuate full ABS on gravel roads to purge the air from within the pump then bleed all lines again. I work at the Proving Ground in Michigan.......have seen this before. Here's a link for a new replacement module:
http://www.ebay.com/bhp/silverado-abs-module

 

[Billdog350]

Hodge, I'm more familiar with the newer 2001+ 2500HD's but I did have a K1500 in your body style and motor as well.

I believe you have hydrovac brakes on there, those master cylinders can get flaky and have all sorts of issues between leaks, spongy pedal, etc. Not saying your issue is the master, however I have heard less about ABS failing and more about master cylinders in the past many years...

Like others have said, make sure to bleed the system well and activate the ABS to properly purge the air from the system.

Looks like nzzshl gave you some good advice and where to find the ABS units if you do need to go that route.

 

[North Idaho Wolfman]

Hodge,
You were right, quicker advice than the truck forum!

I too have had issues with trucks and ABS brakes doing what you describe, the master cylinder and proportioning valve will do all sorts of crazy things when there is the slightest leak in the system.
Might start with replacing the pump / control unit and then give it a good bleeding and if that doesn't clear it up go after the Master cylinder.

 

[skeets]

If you wnt to that silverado yeah that site does suck big time, I went with some issues I need help with,, and found more info on youtube than anybody there offered

 

[hodge]

Appreciate all of your help, guys. But, the truck is in a capable shop who is sorting through the issues. It was a bad pump, they installed a used pump from a salvage yard that is also bad, and instead of trying again with another salvage yard pump, we'd like to find a new or reman unit. So, that is what I'm inquiring- anybody know of a source that isn't readily findable through a web search?

Idaho, you are right! I got more response in a couple of hours, and good, quality feedback, compared to a Chevrolet-dedicated site. A moderator finally welcomed me, but didn't offer any advice or wisdom. Once again, OTT puts other sites to shame!

 

[millsrv]

I have had great luck using Ebay as long as you look carefully at the seller and they have excellent customer feedback. There are many to choose from there both remanufactured and used.
You just need to make sure that this problem is diagnosed correctly. Returning a part because it turned out not to be the problem is a problem.

 

[eipo]

Not sure if this will work, if not go to rockauto.com and find your truck.

http://www.rockauto.com/en/catalog/...53080,brake/wheel+hub,abs+hydraulic+unit,1588

 

[Tooljunkie]

I checked rockauto, they dont show it.
Tried cardone remanufacturing but the site is wonky. They rebuild near anything.

If finding a good one will bear near impossible, maybe its time to consider eliminating the abs unit completely. Considering the alternative is not knowing if you can stop when you really need them.

 

[eipo]

The link shows the entire unit, motor, valve body....

Unless of course I'm thinking of the wrong part.

 

[hodge]

I have searched, and searched, and searched- and I'm pretty good at it- and I haven't found anything but used. That includes Ebay, Rockauto, and the like. The local Chevrolet dealership can't get one. I had hoped that there might be one on a shelf someone, covered in dust, taking up space. Nope.
At this point, doing away with the ABS system isn't possible- it has to be in place and functional for the truck to pass inspection. Otherwise, it would be out of there.

 

[D2Cat]

When you guys click on the RockAuto posted link doesn't the ABS show up at the top for $650, or so plus the core charge?

 

[nzzshl]

Appreciate all of your help, guys. But, the truck is in a capable shop who is sorting through the issues. It was a bad pump, they installed a used pump from a salvage yard that is also bad, and instead of trying again with another salvage yard pump, we'd like to find a new or reman unit. So, that is what I'm inquiring- anybody know of a source that isn't readily findable through a web search?

Hodge, I apologize for providing the link for the module on Ebay. It opened the right page but one would have to scroll through them to get to the pumps. Looking specifically at those, I did not see any for the K3500 (4x4). I did go to Summit Racing and saw that they had listings for likely what you need. I would recommend giving them a call.....they have always been on the game for me. They listed AC Delco pumps as one of the manufacturers, a plus in my eyes. They will be in different price ranges. If you need any assistance, pm me.

 

[Tooljunkie]

The link shows the entire unit, motor, valve body....

Unless of course I'm thinking of the wrong part.

I pull up the application and it has description, but no part or price. Canada thing maybe.

 

[hodge]

When you guys click on the RockAuto posted link doesn't the ABS show up at the top for $650, or so plus the core charge?

ABS540281 Reybestos ABS hydraulic unit- not available at Rockauto or Summit.

I think I just found one on Wizardautoparts, for... $756.00.
https://www.google.com/url?sa=t&rct...5FWhJQ0uDlE3P8FWfs47Rw&bvm=bv.116573086,d.cWw

 

[hodge]

Again, thank you so much for all of your input! Still not a single response on Chevroletforum.com.