ABS pump and solenoid pack replacement

OK has anyone replaced the pump and solenoid and pump pack i think ive got some solenoids that are toast.

I have codes 42,46,56 and 77.

I still have to con check the solenoids but think three are poorly.

The question is are there any gotchas ive to watch out for?

I will try to do a write up with as many photos as possible, are there any particular shots anyone wants?

Nigel

mmmm...why dont ya just delete em?

Robo, when you do the ABS Delete with the hardware you have found to do it with, will you do a write up for us, thanks.

Nigel, there was someone who had to replace the whole assembly a while back and took some pic's to show us.
I don't think he actually ended up doing the job himself but did disassemble the unit after he had it replaced and showed us the insides and how messed up everything was and gave some input. If you can find his writings on it you may be able to PM him for some more detailed specifics.
I think it is a straight forward job except for the tricky part of bleeding all the air out of it. I think a combination of gravity bleeding and vacuum bleeding is going to be necessary.
I haven't looked at what the FSM or any other technical source says about it though.
If you do an Advanced search for ABS or EBTCM maybe you'll find what I'm referring to.
Good Luck

Cos i actually like the ABS and although i have driven all over the world and hold an advanced driving licence and like the idea of a little mechanical help in a high stress environment!

tounge in cheek.....

nigelf wrote:

I have codes and 77.

Does this mean DTC 77? That's a Delivered Torque Circuit fault...and I'll assume your Traction Off light is on? In a nutshell, The PCM tells the EBTCM (located on the ABS pump) if it needs to use the ABS to correct for wheelslip. Your ABS will still work, but your traction control won't. Usually the EBTCM is to blame for this fault, NOT the pump motor. Please list all codes you have if possible so I can help you further.

Sorry re posted the correct codes ... (whoops) 42,46,56 and 77

The 77 is probably a historical one as i tried an abs unit from an aurora !!

Thank you for clarifying that! We woulda been barkin up the wrong tree!
Below is the schematic of your ABS pump and it's respective codes. Looks to me like....YES your pump is done. Your RF, LF, and LR outlet valves are to blame. We can do a fairly easy test to make sure it's the pump....

Disconnect the big 2-wire connector on the pump (marked 13-14 C1 on diagram). Use a voltmeter set to ohms (ignition off), and test for continuity (.3 to .6 ohms) between the terminals on the pump, not the pigtail. If no continuity, replace the pump.

If there is continuity, check for resistance between pin #14 and the body of the ABS pump. A correct reading should be O.L.. If anything other than O.L., replace the pump.

Do this test first to determine if it IS the pump. If all of your readings come back OK, we need to diagnose more as the EBTCM may be the concern

i will

robotennis61 wrote:

i will

Thanks, i would appreciate it. please provide the vendor source for the replacement parts and anything else you think is pertinent to doing the job.
Rick

OK, i measured the resistances and all measured ok 3 or 5 ohms for the solenoids from the plug that goes into the abs unit. The pig tail to the solenoids is a short (pins 13 and 14)

The twist connector pins and socket look good with no corrosion.

im thinking its back to the abs computer, i did try a replacement but it was from a different car type and was out by one digit in the part number! it did stop the traction lamp from lighting but i think its a red herring.

ok are there any other checks i can try ?

Nigel

nigelf wrote:

OK, i measured the resistances and all measured ok 3 or 5 ohms for the solenoids from the plug that goes into the abs unit. The pig tail to the solenoids is a short (pins 13 and 14)

The twist connector pins and socket look good with no corrosion.

im thinking its back to the abs computer, i did try a replacement but it was from a different car type and was out by one digit in the part number! it did stop the traction lamp from lighting but i think its a red herring.

ok are there any other checks i can try ?

Nigel

Sorry to repeat myself.....but did you check from pin #14 to the body of the pump? This will tell you if ANY of it is shorted to ground....O.L. is the proper reading.

owww ... dam ... forgot that one!!!

will check tomorrow today was a great sunny day ..tomorrow is said to be better!

Nigel

oh and heres the pig tail plug with pin numbers

Thanks for the pic and the Numbering of the pins.
Will come in handy in the future I'm sure.

ppump pig tail pin 14 to chassis Resistance checks carried out and was open cct (5meg)

nigel

nigelf wrote:

ppump pig tail pin 14 to chassis Resistance checks carried out and was open cct (5meg)

That's a good thing....means none of the internals are grounded. I'd try my luck at getting a used EBTCM to try (for the same year, model), unless you want to check all the wires from the EBTCM connector to the PMV.

---Plug back in the PMV, and unplug the EBTCM connector (on the left strut tower).
---Put one lead on pin #3, and check for resistance to 2, 20, 21, 38, 36, 54, 18, and 55.....these are all your outlet valves AND wiring in one shot. As you can see by the schematic I posted, pin #3 and all of those mentioned are connected. ALL should be less than 10 ohms. . If any excessive resistance is found, a bad wire(s) needs to be fixed.

If you're confident in all of your findings, replace the EBTCM

Ok im very confident in my findings so looks like time for a replacement EBTCM !

N

ok purchased $44 inc shipping

Part number 25625047 from a 1995 riviera.... (not the GS PA the other one was from!

Very Inexpensive, considering what it does.

well it is second hand .... but was from motrad so i presume its going to be a goodun apparently scanned and checked working on removal.i will be really happy if this works.

If I'm not mistaken the EBTCM is plug-and-play without any programming. Make sure to clear the codes in the PCM after installation. Good Luck!

Well the pump unit arrived so had it apart ...... as you do! and took some snaps of its internals so you guys can see whats what!

pump split from solenoids


closeup


inside solenoid compartment


side of solenoid output ports


Nigel

Looks like a little cleaning and you're "good to go" - I think clean brake fluid or new alcohol (denatured ethanol, methanol, usually sold as a gasoline additive to absorb the water, sometimes called "dry gas" or "Heet(TM)" in the US) will work. There is a distilled spirit called "Everclear" that would also work, don't get it on your hands it is *very* drying. Perhaps an Everclear analogue is sold at a liquor store near you, it sould be just pure 94% alcohol.

Albertj

Nigel,
Once get a chance to remove and replace these unit's, will you dis-assemble the old one and see if there is any difference inside the solenoid housing, such as excessive corrosion or some other obvious reason for failure..!! Does the fluid flow around the solenoids, I didn't think so, but can't tell from the pictures where the normal fluid flow is.
Thanks.

Sure thing Rick,

I actually got the EBTCM today pluged it in ... still abs and traction lights .... oh boy did i have a swear word or three!

so i slaved in the pump and the abs lamp went out. further measurement and found a high resistance on pin 5 to 14 where i expected 3 or 5 ohms. so it looks like the pack is to be replaced this weekend. i will take broken one apart as it may be repairable if its a cable dry joint or such.

The inside where the wiring is should be dry, no brake fluid in there.