85 928 Euro Brake Weirdness
03-20-2016 | 05:15 PM
#1
Thread Starter
4th Gear
Joined: Oct 2014
Posts: 4
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85 928 Euro Brake Weirdness
I am trying to restore my dad's '85 928S Euro that has been in my family since it was first brought to the States. Most things have been done and worked out pretty much as expected, but we have a new issue that before I dive in with all new parts I was hoping someone here could point out a good direction.
For the longest time the ABS light would come on intermittently. We changed the relay and then removed each sensor and flushed tons of crap out. All the sensors where put back in, none were replaced, yet.
Before this was done the brakes stopped fine, no ABS usually but they worked well. Now there is a lot of feedback in the brake pedal, the stopping distance is terrible and when you slam them the left front and right rear wheels lock.
Sensors? Module? Both?
Thanks,
Erik
For the longest time the ABS light would come on intermittently. We changed the relay and then removed each sensor and flushed tons of crap out. All the sensors where put back in, none were replaced, yet.
Before this was done the brakes stopped fine, no ABS usually but they worked well. Now there is a lot of feedback in the brake pedal, the stopping distance is terrible and when you slam them the left front and right rear wheels lock.
Sensors? Module? Both?
Thanks,
Erik
03-20-2016 | 09:15 PM
#4
Former Vendor
Joined: Feb 2005
Posts: 15,230
Likes: 2,489
From: Anaheim
I am trying to restore my dad's '85 928S Euro that has been in my family since it was first brought to the States. Most things have been done and worked out pretty much as expected, but we have a new issue that before I dive in with all new parts I was hoping someone here could point out a good direction.
For the longest time the ABS light would come on intermittently. We changed the relay and then removed each sensor and flushed tons of crap out. All the sensors where put back in, none were replaced, yet.
Before this was done the brakes stopped fine, no ABS usually but they worked well. Now there is a lot of feedback in the brake pedal, the stopping distance is terrible and when you slam them the left front and right rear wheels lock.
Sensors? Module? Both?
Thanks,
Erik
For the longest time the ABS light would come on intermittently. We changed the relay and then removed each sensor and flushed tons of crap out. All the sensors where put back in, none were replaced, yet.
Before this was done the brakes stopped fine, no ABS usually but they worked well. Now there is a lot of feedback in the brake pedal, the stopping distance is terrible and when you slam them the left front and right rear wheels lock.
Sensors? Module? Both?
Thanks,
Erik
The most common intermittent problem is the short looms that run from inside the engine compartment to the front spindle.....if the problem is very intermittent, these can be tough to confirm being bad by checking continuity. As they deteriorate more, it gets easier.
Clean both of the relays on top of the ABS pump. Also clean the ground wire to the pump. Remove both of the wiring plugs to the pump and clean them. Make sure the electric motor for the pump runs....pretty simple to jump it and make sure.
For some crazy reason, rodents love the loom that runs to the ABS pump, along the inner fender. When the inner fender panel is out to clean the relays and ground wires, check that loom....it is common for it to be damaged.
Clean the main power relay on the fuse panel. Test it and make sure that it works.
Clean the main power fuse to the relay and contacts, while you are there.
Make sure you have power coming out of "87" on the ABS relay, when you are done. (H25 on a US car.)
03-20-2016 | 11:27 PM
#5
Thread Starter
4th Gear
Joined: Oct 2014
Posts: 4
Likes: 0
I feel sorry for you guys trying to isolate ABS problems without a shelf full of "test" pieces, like I have....this can be a really tough road.
The most common intermittent problem is the short looms that run from inside the engine compartment to the front spindle.....if the problem is very intermittent, these can be tough to confirm being bad by checking continuity. As they deteriorate more, it gets easier.
Clean both of the relays on top of the ABS pump. Also clean the ground wire to the pump. Remove both of the wiring plugs to the pump and clean them. Make sure the electric motor for the pump runs....pretty simple to jump it and make sure.
For some crazy reason, rodents love the loom that runs to the ABS pump, along the inner fender. When the inner fender panel is out to clean the relays and ground wires, check that loom....it is common for it to be damaged.
Clean the main power relay on the fuse panel. Test it and make sure that it works.
Clean the main power fuse to the relay and contacts, while you are there.
Make sure you have power coming out of "87" on the ABS relay, when you are done. (H25 on a US car.)
The most common intermittent problem is the short looms that run from inside the engine compartment to the front spindle.....if the problem is very intermittent, these can be tough to confirm being bad by checking continuity. As they deteriorate more, it gets easier.
Clean both of the relays on top of the ABS pump. Also clean the ground wire to the pump. Remove both of the wiring plugs to the pump and clean them. Make sure the electric motor for the pump runs....pretty simple to jump it and make sure.
For some crazy reason, rodents love the loom that runs to the ABS pump, along the inner fender. When the inner fender panel is out to clean the relays and ground wires, check that loom....it is common for it to be damaged.
Clean the main power relay on the fuse panel. Test it and make sure that it works.
Clean the main power fuse to the relay and contacts, while you are there.
Make sure you have power coming out of "87" on the ABS relay, when you are done. (H25 on a US car.)
Erik