When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Jeff, if a brake hose has failed internally the ABS system will release the pressure but the failed hose doesn't. Had it happen on my 89. Are the brake hoses original?
Jeff, if a brake hose has failed internally the ABS system will release the pressure but the failed hose doesn't. Had it happen on my 89. Are the brake hoses original?
They are, but nothing feels out of sorts under any other conditions...
'Spose I should get a set from Mark down in LA...he's the closest/cheapest shipping option.
The ABS in my car goes through a barely-detectable 'self-test' routine at first brake application, but only if it's been parked overnight or longer. I hear the pump cycle and the pedal drops slightly. This is the 'first forward stop after the garage, so it's low-speed and easy to detect. Does your car do this?
There are some other simple/obvious things to look at. Power for my ABS unit is fed from a dedicated wire between the alternator and a screw in a barrier-strip terminal at the left front corner forward of the power steering reservoir. This connection is lifted for timing belt replacement, and probably deserves the same regular care and cleaning you give to the connections at the jump post terminal and the ground connections.
The ABS pump is very similar to the PSD pump used in 90+ cars, and needs regular flushing. And probably exercise too. There may be a write-up somewqhere that describes the relay connections (onboard the ABS unit and accessible through the LF fender with forward liner removed.
---
In my limited experience, I can't think of a way that brake lines would somehow inhibit ABS function wile still allowing normal pedal braking.
---
The ABS in our cars is a primitive (by current standards) three-channel system that treats the two rear calipers as one, as far as hydraulics go. While ABS goes a long way towards balancing braking in emergency situations, it's no substitute for balanced braking. Considering the car's history in a corrosion-free corner of Florida, it still might be prudent to do a full inspection and possible caliper refurbish on the car just to be sure. I'm sure there are already-rebuilt ATE calipers from several sources, usually for less than the cost of parts and the aggravation/risk factors involved. If they don't already look great and move freely on their own that is.
try it a few times.... mine has done this occasionally,when really hot at the track. but i get the ABS light going on , and i can feel it locking up. if i dont hear and feel the early warning vibration, i know somethings up. i go back and forth from using the ABS to disconnecting it entirely, so i have a good feel for it. sounds like you have an internal ABS pump issue that might need to be worked out. did you do the test again to see if it was engaging? another test , is to floor the car in 3rd gear and apply the brakes too (with great pressure) this will work the ABS pump as cycles longer than just a high speed stop would. make sure you have LOTS of clear hyway to be safe. front and behind.
I do NOT feel the ABS test in the AM backing down my steep as hell driveway...
ive never felt anything on start up. try a few more tests. better yet, jack up the car in the rear, put stands under the car! and do some 4th gear WOT, braking to test abs engagement. this will get the pump singing and you might have had some air in the system.... if its a bad connection back in the rear juction, that will show as a problem, but the light should come on. it might be an anomoly so further testing might be good
9 Vehicles Porsche Helped Engineer that Aren't Porsches
Slideshow: Long before engineering consulting became trendy, Porsche was quietly helping other automakers build everything from supercars to economy hatchbacks.
9 Features and Characteristics That Only Porsche People Understand
Slideshow: Some brands build cars. Porsche builds traditions, obsessions, and a few habits that stopped making sense decades ago but somehow became part of the charm.
This Builder Is Turning Heads With Its Slantnose 911 Creation
Slideshow: A small Polish tuner has reimagined the Porsche 911 Slantnose for the modern era, blending 1980s nostalgia with widebody tuning culture and serious performance upgrades.
Porsche 911 GT3 Artisan Edition Pays Homage to Japanese Culture
Slideshow: Porsche has created a Japan-only 911 GT3 Artisan Edition that blends track-ready hardware with design cues inspired by traditional Japanese craftsmanship.
Porsche Reveals Coupe Variant of the Electric Cayenne With a Fresh Look
Slideshow: Porsche's latest electric Cayenne Coupe blends dramatic styling with supercar acceleration, turning the brand's midsize SUV into a 1,139-horsepower flagship.