ABS ON 172

[ian172]

Hi,

i have a mk 1, 172 (2000) and keep having nasty experiences with the abs brakes.

The other day i was approaching a roundabout at an average speed when at the last minute some tw*t decided he wanted to go round the roundabout instead of straight across like he first planned, i applied the brakes heavily but the abs kicked in, the car didnt slow down at all and i careered onto the roundabout infront of this car, how i missed him i dont know.

It was a dry, hot, sunny day and if the brakes had of worked i would have had plenty of time to stop. Normally the brakes are the nuts, but when this happens its bloody scarey and dangerous. I find if i pull into say a carpark quite quick and apply the brakes as im turning the abs just comes on and the car does not stop?

Has anyone else had this problem with there 172 or does anyone elses do the same thing??? Would appreciate any advice???

 

[telford_mike]

If you go over a manhole cover or something like that it can trigger the ABS. Mine operates every morning approaching an island on the way to work.

 

[BenR]

They dont like it when your on full lock.

 

[clio_mad]

Mine isnt a 172 but I have had a similar experience. I was approaching a set of traffic lights which were on amber. I was gonna chance it a go thru but I noticed a traffic camera, so I slammed on my brakes. The brake pedal stated to judder, the car didnt stop and I careered straight over the stop line into oncoming traffic (No crash fortunately!!!).

 

[JAY172]

maybe if you didnt have abs the wheels would have locked and you would have skidded into the roundabout at a lot greater speed then you did. very unusual fault if there is one so best to get it on a renault diagnostic machine to make sure all the wheels sensors are reading correctly etc.

 

[ian172]

no there was plenty of time to stop, but with the abs on the car didnt slow down at all.

when i bought the car bout 6months ago i noticed this and got renault to check it out and they said that everything was ok, but this cant be right???

 

[ian172]

any more suggestions???

 

[RPM]

I have had the same problem exept i went through a hedge into a graveyard. Lucky i didnt hit a tombstone. Speed as brake was applied was 10mph A friend of mine who drives slalom/SS with his 172 has installed a switch to turn the ABS off, otherwise it wont brake while turning hard.

 

[ian172]

nasty!!!! so no one else has this problem with there 172??????????

 

[nuppy]

ABS has two stages the first which stops any more pressure being applied to the locked brake this will give the feeling of no extra braking The second stage pumps fluid out of the locked brake giving the pedal the pumping feeling under you foot. The most important thing to remember is that ABS will not shorten the braking distance of a good driver but will give control when you are really in the s*it.

 

[JAY172]

the pumping feeling is from the pump replenishing the inlet part of the brake circuit. there are two valves per brake circuit/wheel. when the wheel skids one valve shuts off the inlet circuit to prevent any more pressure being applied. the second valve releases fluid down the outlet track to reduce pressure at the caliper if cutting the inlet didnt stop the skid. there is a reservoir in the outlet circuit called the accumalator. the pumping sensation you feel at the pedal is the pump removing fluid from the accumalator and returning it to the inlet circuit. as the fluid enters the inlet circuit from the pump circuit it pushes the brake pedal back up slightly. this complete cycle gives you the pumping feeling at the pedal.

 

[Simao]

Had no probs with my ABS except it came on at a junction once when it shouldnt have done, but that was after i had overheated the brakes...twice...ten minutes before. It still slowed me down tho.

 

[FiXX]

yeah mine trigger quite oten when braking over uneven surfaces etc but still stops me well

 

[FiXX]

haha, odd that i should reply to this post and then 10 minutes later thank the lord for abs. A just decided to do an emergency stop in trafic and i would have crashed into her if it were not for abs....