Help me diagnose a braking issue on a Volvo C30

[Marty]

Hey guys

 

My mum has a braking issue on her Volvo, c30, around a 2007, 1.6d.

Basically when shes driving her brakes are very spongy, sometimes she'll brake and there will be barely anything there, the pedal goes pretty much all the way to the floor, sometimes it is just fine. When it does happen if she pumps the pedal the brakes come back to life (pedal firms up) and work fine, but it'll happen again if she doesn't use the brakes for a short period.

It isn't air in the system as when the engine is off the pedal is to the top and solid.

I've had a little look online and there doesn't seem to be anything conclusive - some say dodgy brake booster but it seems to be working fine, the pedal would stay firm if it wasn't. I've had a look over the vac lines and all seems ok.

Could this be a master cylinder issue? I've also read that it could be an abs module problem.

Has anyone experienced anything similar?

 

Thanks in advance

[Shane]

I had these exact symptoms on two of the Mercedes I have owned, both turned out to be the master cylinder. That would be my first thing to eliminate, has it ever had a fluid change?

[Dnk]

I'd bleed the system if its not been done for a few years if ever and go from there, at least you can do that yourself

for not a lot of cash

[Marty]

Thanks for the replies guys

 

Still not got to the bottom of this.

I bought a second hand master cylinder off eBay - i cannot for the life of me find a new one anywhere, except volvo.

The master cylinder was changed and the problem persists? Surely you'd think the chances of another one being toast too would be slim.

Leads me to believe it could be something else.

Would the fluid cause these problems? You'd think once the car was hot and fluid warm that you'd see it everytime the brakes were applied? It's intermittent:search:

[jagman]

There is a Volvo recall on the brake check valve -intermittent brake servo assist and pedal pressure - 2007 cars on

[Marty]

There is a Volvo recall on the brake check valve -intermittent brake servo assist and pedal pressure - 2007 cars on

 

I did spot that on the volvo website and forwarded the info on to my mum, she said that her vin came back with no recalls?

 

I assume if that if the brake check valve was faulty the pedal would still stay firm and the brakes just not work as well?

The pedal on my mums volvo will literally go straight to the floor sometimes with very little braking there. You have to let off and put your foot down again for the brakes to work.

 

I've seen it before on older cars where the rear drum was faulty, the ratchet mechanism that holds the shoe close to the drum had failed, it was backing off between braking causing a similar issue. This volvo has the ratchet type pistons in the caliper, maybe worth looking at? Can't say i've ever heard of them fail.

 

I'd still be convinced it was the master cylinder if i hadn't have swapped it, maybe the other one could be faulty? I don't really want to drop £300+ in to one supplied by volvo just to have the same problem

 

i have come across this too..

 

http://www.vosa.gov.uk/vosa/apps/recalls/searches/expand.asp?uniqueID=517A1A55A2A84BD0802574020030A0C0&freeText=Blank

 

maybe it is the master cylinder:rolleyes:

Edited August 18, 2017 by Marty (see edit history)

[croboy]

I did spot that on the volvo website and forwarded the info on to my mum, she said that her vin came back with no recalls?

 

I assume if that if the brake check valve was faulty the pedal would still stay firm and the brakes just not work as well?

The pedal on my mums volvo will literally go straight to the floor sometimes with very little braking there. You have to let off and put your foot down again for the brakes to work.

 

I've seen it before on older cars where the rear drum was faulty, the ratchet mechanism that holds the shoe close to the drum had failed, it was backing off between braking causing a similar issue. This volvo has the ratchet type pistons in the caliper, maybe worth looking at? Can't say i've ever heard of them fail.

 

I'd still be convinced it was the master cylinder if i hadn't have swapped it, maybe the other one could be faulty? I don't really want to drop £300+ in to one supplied by volvo just to have the same problem

 

i have come across this too..

 

http://www.vosa.gov.uk/vosa/apps/recalls/searches/expand.asp?uniqueID=517A1A55A2A84BD0802574020030A0C0&freeText=Blank

 

maybe it is the master cylinder:rolleyes:

 

Yo, did you ever find out the issue? I'm having something similar with my jza80

[rider]

Yo, did you ever find out the issue? I'm having something similar with my jza80

 

Marty isn't one of our more frequent posters so they may well not be a regular site visitor so they probably won't pick up on your question. You really need to private message him, but unfortunately, you'd need to join up and pay a small subbscription fee in order to send a PM. Alternatively, you can raise your own specific thread question in the Supra technical section and that would probably illicit replies - it could even then be picked up by Marty seeing it'd be profiled as a new topic.