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ThaCrabapple
12-30-2016, 06:58 PM
All, I have recently acquired a 1991 XR7. The cougar runs great, unfortunately it doesn't stop (Only the parking brake works).

Currently there is very little to no brake pressure. Both lights stay illuminated. The hydraulic pump does not turn off(I haven't attempted to let it run that long to find out). It doesn't sound like its "pumping".

Knowing that the pump at least turns on, where should I start?

Thanks for helping out a newbie, the ABS has my head spinning.

KMT
12-30-2016, 07:14 PM
Sounds like you need a new accumulator - hard to find right now, I think.

In the mean time, see: http://www.sccoa.com/faq/Floyd%20ABS%20Article.pdf / Basic Troubleshooting

And yes, don't let the pump run any longer than necessary.

ThaCrabapple
12-30-2016, 07:31 PM
KMT,

I've read that article. Thanks for the post.

I'm a little confused about the system, can ordinary brakes work if the pump fails?

I know no history of the car, but other than the brakes it's in very nice shape with 106k. The front rotors have deep gouges physically etched in them. I do NOT hear the calipers move at all when the brake pedal is pressed.

Creighton
12-30-2016, 11:14 PM
Welcome to the forum!!

Deep gouges in rotors is not good. Replace all 4 wheel brake assemblies ASAP. Brake shop will be able to tell if rotors can be saved. These parts are not terrible expensive but some of the best money to be spent.
New here as well so any updates are great.
Thanks!
Creighton

KMT
12-31-2016, 12:18 AM
can ordinary brakes work if the pump fails?

Sort of...they work until the residual pressure in the accumulator is spent and then require very high pedal pressure and lots of room to stop. Only useful to get off the roadway, in most cases.

In your example, you said the pump is working, so that means the first suspect is the accumulator...if it's not holding/taking a charge, the pump can't reach high limit pressure and will just keep going until it burns out or an internal limiter kicks in. If you don't have full pressure, you don't have normal/assisted braking. The accumulator is responsible for supplying full brake pressure...the hyd pump just feeds it and can't generate full pressure on it's own.



The front rotors have deep gouges physically etched in them. I do NOT hear the calipers move at all when the brake pedal is pressed.

While I'd not expect to 'hear' the calipers actually move, it sounds like someone has gotten their money out of the rotors and it's time all calipers, pads & rotors were inspected for replacement. I'd not plan on driving that XR until it has had some serious brake work done. Good luck.

Ken

ThaCrabapple
01-01-2017, 09:51 AM
Sort of...they work until the residual pressure in the accumulator is spent and then require very high pedal pressure and lots of room to stop. Only useful to get off the roadway, in most cases.

In your example, you said the pump is working, so that means the first suspect is the accumulator...if it's not holding/taking a charge, the pump can't reach high limit pressure and will just keep going until it burns out or an internal limiter kicks in. If you don't have full pressure, you don't have normal/assisted braking. The accumulator is responsible for supplying full brake pressure...the hyd pump just feeds it and can't generate full pressure on it's own.



While I'd not expect to 'hear' the calipers actually move, it sounds like someone has gotten their money out of the rotors and it's time all calipers, pads & rotors were inspected for replacement. I'd not plan on driving that XR until it has had some serious brake work done. Good luck.

Ken

I have already ordered rotors and pads from Rock Auto. I searched for an accumulator and came up empty handed.

I've read extensively on the conversion to non-ABS brakes and I'll be taking that route. Seems like the most cost effective and reliable step for me.

RalphP
01-01-2017, 02:08 PM
I have already ordered rotors and pads from Rock Auto. I searched for an accumulator and came up empty handed.

I've read extensively on the conversion to non-ABS brakes and I'll be taking that route. Seems like the most cost effective and reliable step for me.

Yah, the conversion was the path for me.

However, if you decided to keep the Teves Mk II Integral ABS on your car, and don't need to drive it, Victor over at Spinning Wheels SC will be selling more when he gets more made ... http://spinningwheels-sc.com/hydacaccumulatorballs.aspx

(I just got fed up with them on my car; so I converted to conventional. Best decision I made on it, IMO.)

RwP

TbirdSCFan
01-02-2017, 02:09 PM
Yah, the conversion was the path for me.

However, if you decided to keep the Teves Mk II Integral ABS on your car, and don't need to drive it, Victor over at Spinning Wheels SC will be selling more when he gets more made ... http://spinningwheels-sc.com/hydacaccumulatorballs.aspx

(I just got fed up with them on my car; so I converted to conventional. Best decision I made on it, IMO.)

RwP I'm reaching the end of my rope on these Teves IIs. For a long time, I could swap out components and buy a few accumulators, and an occasional pressure switch, and all was fine, but 27 year old shaft and case seals just aren't holding up anymore so that strategy isn't working out so well. The Hydroboost (http://powerbrakeservice.net/new-1989-1992-ford-t-bird-hydroboost-brake-booster.html) units are good alternatives too and new.