View Full Version : leaky ABS pump motor

04-21-2003, 12:04 PM

I've (finally) traced an intermittant brake fluid leak to the hydraulic pump/motor assembly. The question now is what is the proper fix----is the pump and motor available as a service part, or am I looking at a whole rebuillt MC unit from Prior? ($$$)

Does anyone out there have experience with this, and can point me toward a less expensive solution than the remanufactured MC?

Thanks for any insight!

1990 Tbird SC

04-21-2003, 07:11 PM
Hey Al, Where was it looking wet? Ive had an on and off leak too for like two months now. Its really pissing me off. For me, a little under the resvior hose on the assembly is wet , all to the right on the lower part of the pump is wet, it streams down towards what looks like a weap hole on the bottom of the assembly, down the steering boot, and on to the cat. Leaks when ever it feels like it. I feel the same way you do, a new pump is just to expensive. Even a remanufactured one is alot. Hopefully you can tell me if this sounds like the same leak you just figured out. Thanks

04-22-2003, 01:18 AM

The symptoms I have are:

1) Intermittant leak---it'll be fine for days, and then it'll let go with a couple ounces of fluid. I got used to keeping a few extra bottles of brake fluid in my trunk.

2) The only place it was wet was on the underside of the pump motor and pump assembly. These are the cast aluminum (?) block that the accumulator screws into, and the cylindrical pump motor directly outboard of it. It was dry around the accumulator nipple, and also dry around all the brake line fittings.

After some examination, I believe the fluid is coming out the weep hole in the pump motor or between the pump motor and the pump. Either way, I need to replace or rebuild that assembly.

Hope this helps---let me know how you do.


04-22-2003, 09:44 AM
Need more info;

Current Accumulator original?

Are you rear calipers stuck?

04-22-2003, 10:42 AM
I've got the same general leak happening too! Can't see where it's coming from, but every now and then on acceleration my red brake light comes on. Once, I had a lot of white smoke come out near the ABS assembly, apparently when brake fluid dripped onto the manifold... New accumulator from Prior which I've since tightened as best I can, but its hard to do without that fitting on top like the stock one has... Braking performance isn't affected, though.

04-22-2003, 11:07 AM
there was a sensor that was leaking on mine out the tip where the wire connectors are on it. not sure what it was called, but it screws into a box that is connected in the line. if you look up under the car, it dripped right onto the catalytic converter. I think it was like $80 from ford for this sensor.


04-22-2003, 11:11 AM

As for my symptoms---the accumulator is about two years old. The rear calipers aren't stuck---braking seems to work fine as long as I keep the fluid topped off.


Jeff Bratton
04-22-2003, 12:39 PM
I had the same problem of leaking too, I searched and searched with a mirror and found that is was that of the sensor/ connector (GREEN) in color was the ending result of the leak. I unscrewed it from the pump and found that the O-Ring on it was bad. Place a new one on it and never had the leak again.

I orginally to it to the Dealership and they told me that they could not find the leak, but tested everything and came up with the computer being bad.... I then said BULLS*@T! He then tried to sell me the thing at over 750 bucks!!! I said No thanks, I find the leak myself... They were Mad for what I said but I knew that having a bad control module and a leak are to different things.

I drove it home and found my problem described above the very next day!

P.S - Changed my Accumulator at the same time from 'Prior Manuf... at cost of 99 bucks. Never stopped better and no leaks. Good for another 165,xxx miles hehehe

You will need to take the Accumulator off anyways to take the pump off to get to this sensor/connector, if indeed this is your problem.

Jeff B.

04-22-2003, 06:56 PM
Al - That sounds exactly like my problem but you just wrote it better. I just get to dam agravated everytime i tried to find it. So I just add some every other day, and try to forget about it. You are the man for doing the grunt work and sharing your info with us!

3tbird - Accumulator changed like two months ago, definatly not leaking. Rear brakes seem fine.

joenintiesc - When your brake light comes on during acceleration that means your low on fluid.

Jeff B. - Do you remember what sensor it was? And if its the pressure warning switch, how did you get it off? Did all the brake pressure come out, and did you have to bleed the brakes? Thanks

Jeff Bratton
04-23-2003, 01:14 AM
Boosted89sc - I have checked my manual and yes that is the sensor ( Pressure warning switch ) - 5 Pin connector. I do know that it was the green one... believe it was about 2 1/2" long or so & cylinder shaped as well and the bottom of it is where you would use a wrench to loosen it. 7/8" maybe, really can't remember.

Yes... You will have to pump the brakes 20 to 30 times with key off to discharge the pressure in the system before disassembling.

Getting to it is easy but requires you to take off your wipers, cowl panels and the wiper motor. take those off and it well make life soooo much easier.

Once you do all that discharge brake system like I mentioned above, then take your Accumulator off, making sure you do not lose or damage the O-Ring.

next you will need to dis-connect that little brake line ( the 5" to 6 " wavy one ). then dis-connect the hose from the reservoir to the pump. leave the one end on the reservoir and just plug the other end with something.

then your next step is to take the pump off. there is a plug on the shock tower side (pump motor connector) you will need to unplug. the other side... there is a small headed bolt with like a rubber type gomment/ fitting which ensures pump to move freely when pump comes on. take this bolt off and you should at this point take the pump out through the hole created when you took the Accumulator off. Watch as you are pulling out the pump to help feed the pump motor wire through and around all the other wiring / hoses/ brake lines. Will hang up and piss you off if you aren't watching what you are doing. lol!

now that you have the pump out, you now can get to the pressure waring switch connector. As I mentioned in my previous posting there, on replacing the O-ring. Before Re-installing the switch... lubricate the O-ring with a little bit of brake fluid. now you are ready to install everything back. GOOD LUCK! :)

I really hope I haven't confused you or left anything out here and I hope you can follow what I wrote as well. I hope this Helps!! If you need any help just AIM me at : brattmanjc89. or email me at [email protected]

P. S. - I surprising did not have to bleed my brakes neither I thought I was going to have to when I put everything back together and started my car and watched to make sure both the ABS light and the brakelight to go off after about 10 seconds, I then pumped my brakes and they were hard. I then drove it out of the garage to test drive it, making several quick stops.... all was COOL! I then was Very happy!! But this does not mean that you might have too though. It wouldn't hurt to do so anyways, just to make sure.


04-23-2003, 09:53 AM
Thanks for allthe info guys! Maybe we'll get to the bottom of it yet...

boosted89SC: Thanks, but I already figured out I was low on fluid because it is leaking! ;)