Do it yourself ABS module repair. Topic is solved

louis_m_c · Post by **louis_m_c** » 09 Sep 2008, 16:51

I just tried it on a 850 1996...

I broke all the edges top of the box trying to open it...

Using a flat screw driver to open it I managed to damage a transistor...

BUT ! I removed a transistor of the same size and color from an old computer hard disk drive and soldered it at it's place *I was telling to myself it would not work*... Then I resoldered every pins and put everything back. While screwing the box back into place I droped on of the screw and never find it again...

man.... it work ! no more ABS / Track Light ! I tried the ABS while driving at 50 km/hr and the brakes just did very fine!

All I need to do now is to remove the box again, fill the thing with black silicone glue, find another screw and put it back and forget it for eternity.

My tip: use a metal saw or a dremel to remove the cap of the box, less chance of destroying something I beleive. And be very carefull with screw driver not to damage anything inside. I was lucking my attempt to repair the transistor worked. And finally, buy the black silicone glue before not after the repair...

madorion · Post by **madorion** » 09 Sep 2008, 17:45

Hi All,
Mine has press on jam washer/clips, probably the same as everyone elses. A little WD40 or PB Blaster on the clips and (through the unit) retaining posts, wait 5 min. and they pry right off w/little screwdriver.

Radio shack sells a fiberglass filament eraser brush, great for cleaning and polishing circuits and solder areas. I also recommend using a flux with the solder. Alcohol with a toothbrush is great for removal of flux and other impurities. Thoroughly clean the board and let dry before you coat/assemble the module.

Pure clear acrylic enamel(same that is in spray paint without the color) is used for sealing printed circuit boards to guard against moisture and shorting. This can be used to "conformal coat" the board after the repair without the need for silicone. It is easily removed with a fiberglass scrub brush, so repairs can be done quickly.

The clear acrylic enamel sells for two bucks a Walmart. Use silicone Rubber(GE) around the edges before assembling, but thats all you need!

louis_m_c · Post by **louis_m_c** » 09 Sep 2008, 17:52

There was no clip to open my box simply a sticky silicone gel or something alike... I beleive there must be a way of removing it in a better way. I tought of screwing my box on a wood piece then making myself a 4 ways pivot to push on all the sides of the box at once... But unless I would like to make business in Volvo ABS repair I don't think it worth the trouble...

madorion · Post by **madorion** » 10 Sep 2008, 12:32

My ABS unit had hollow, round, metal tubes that the mounting bolts slid through to attach the module to the solenoid stem assembly. The retainers were press on friction washer clips, cheap, but work!

s70gltguy · Post by **s70gltguy** » 21 Sep 2008, 23:44

Thanks for the great ABS Control Module overhauling tips you have posted. I fixed mine over this weekend following the procedure. I would encourage anyone with basic solder skills to give it a go themselves. It is really simple to re-solder the pins with a 40 to 60 watt soldering iron.

Removal and re-installation of the unit is a fairly simple process. You get a #5 torx female socket (in a set at Harbor Freight for $7.99) or you can use a 4mm socket for the mounting bolts.

Once the unit is removed, the only hard part was opening the black plastic case. I found that using a dremel with a cutoff wheel running it about 1/4" down below the lip of the lid and trimming all around the case. Warning : If you cut above this area, toward you could possibly nick the circuit board which is just 1/8" away from the plastic case. Use gentle shallow
cuts with the tool.

A silicone sealant or RTV sealant is used around the case putting it back together. Put a good continious bead so it seals out moisture. Allow to dry for a day before reinstalling.

I had all the ABS, Brake and check engine go out on my 99 S70 GLT after putting the unit back in (before driving). Odometer (was going to dashes) and speedometer (was dropping to zero) began functioning normal again too.

Total time is 8 hours by a semi skilled home mechanic.

kevinj · Post by **kevinj** » 06 Oct 2008, 18:26

greetings! not for the faint hearted and hands are going to be sore, mostly right hand around the middle two fingers, keep trying and you perhaps will get the module loose then the fun begins.. send it out. it will be well earned money well spent in the long run.
also make sure you have a magnet the little e5 gets loose and your doomed for the day

fredneck · Post by **fredneck** » 14 Oct 2008, 18:35

I'm getting in on this late, but you guys are all nuts. Pull the abs, send it to Victor, go watch the game, have a few cold one's, and when it comes back in a few days, put it back in. Coast to coast over Labor Day weekend and it came back on the 6th day. What's not to like? If Victor would run for President, I'd have an easier time making up my mind.

Post by **MadeInJapan** » 14 Oct 2008, 19:02

Hey, thanks for joining, fredneck. It's nice to have another enthusiast aboard- I'm sure Victor thanks you!

Post by **Ozark Lee** » 14 Oct 2008, 19:20

Fred,

All of the posts and writeups on this site or any other site come with an implied caveat on the level of your comfort and competence. If you are not comfortable doing it yourself then by all means you should send the module to one of the re-builders or take it to the nearest dealer. What we try to do here is exchange tips and tricks to - hopefully - keep ourselves out of the poorhouse on what would otherwise be very expensive cars to maintain.

By reputation Victor is one of the best, if you choose to send the module off for repair I would highly recommend him.

As an experienced electrical engineer I have no fear of soldering and I have a feel for how much heat is required on a given joint and I can see when the solder has flowed properly. I have soldered 10s of thousands of solder joints in my life so I have a tremendous amount of experience at it.

Thank you for your contribution,

...Lee

Casper850 · Post by **Casper850** » 16 Oct 2008, 18:35

I pulled my module today in an attempt to fix but ran into a few snags. The first snag I encountered was I didn't have an E-5 torx or 5/32" socket..nor could I find one locally. I did purchase a 4mm 1/4" drive socket that worked perfectly.

Snag two was discovered immediately after pulling the module. Someone had already been inside the module. The case was already cracked and had black permatex around the seam. A greasy liquid was seeping out of the crack in the case..I'm not sure if it was simply water/condensation?

Snag number three was encountered after I pulled the module. The module was held together by 4 circlips that I took the Dremel after fighting w/ them for about 15 min to no avail. I also used the Dremel on the seam in an attempt to help the halves separate. I eventually used a bi-metal sawzall blade by hand to cut open the seam.

Snag four was the membrane laying on the circuit board refused to peel off in a nice even sheet. I have a pile of about 100 small pieces of membrane laying on my workbench. I don't know what I'm going to use to cover the circuit board once this little project nears completion...any suggestions???

On top of everything else...the solder joints look fairly healthy on the circuit board minus two that have near-microscopic cracks at the base of the joint.

I'll be amazed if my ABS/TRAC light go off once this module is replaced..time will tell I guess.