16v205 9 Posted April 22, 2006 Hi Got a weird brake problem and wondering if anyone can help diagnose whats going on as im stumped Im running 1.6 drums on the back, gti-6 brakes on the front and a 23.8mm M/C off a 406. The lines are still split front and back like original. The car is losing its brake pedal and going to the floor when it travels at 2/3mph or is stopped still. It doesnt always happen though, sometimes it can be ok. It feels just like air is getting into the brakes somewhere but there isnt a noticeable leak and fluid is new. When driving although the pedal has a fair bit of travel it bites ok. Its not as effective as it was before the problem started but its not too bad. I changed the slaves in both rear drums for new 2 days ago and re-bled the system, felt exactly the same and we still intermittently lost the pedal at low parking style speeds. This made be think it was the M/C allowing fluid to pass the piston seals, so with the help of Anthony he swapped the M/C for another from a breakers yard and we bled the system again last night. Exactly the same pedal and feel, with intermittent loss of the brakes. The pedal is not going hard so ive not looked at the servo being faulty. So in the middle of the night last night, well 4am anyway I changed the front right brake hose as it had come away and rubbed on the inner wheel and created a flat spot. Re-bled the system again and still exactly the same. Pedal works okish until stopping and tesco to put fuel in when I ran past the fuel pump Has anyone got any ideas about what could be happening intermittently like this. Please help Cheers Rich Share this post Link to post Share on other sites
hengti 2 Posted April 22, 2006 i've had this before and it was the m/c if it's a scrappy m/c, is it possible that that one has also had it? Share this post Link to post Share on other sites
16v205 9 Posted April 26, 2006 Sorry, had to bump this. My dad and myself have been through the car front to back, there isnt a fluid leak anywhere and the pedal still randomly drops to the floor at parking speeds :S Would it be likely/******* unfortunate to have a second 406 faulty master cylinder which shows the exact same intermitant problem with the same sort of frequency? If so wheres the best place to get a m/c rebuild kit from? Cheers Rich Share this post Link to post Share on other sites
C_W 3 1 Cars Posted April 26, 2006 It does still sound like the master cylinder; a faulty servo would just result in a firm pedal if it didn't work. I'd go for the safest bet and get a new master cylinder, they're around £30 usually from GSF. Share this post Link to post Share on other sites
Anthony 1,003 Posted April 26, 2006 I'd go for the safest bet and get a new master cylinder, they're around £30 usually from GSF. 406 ones are unfortunantly alot more - from memory about £80 or so. As I said at the time the symptoms still seem like an MC fault to me and maybe you were just really unlucky getting two with the same fault. I'm happy to send you the spare 406 one that I've got in my garage if you want to try another before buying a new one, as the chance of getting three MC's with identical faults has to be remote enough to effectively rule it out? If there's no leaks though and the slave cylinders are new, I can't see what else it can be in all honesty Share this post Link to post Share on other sites
Foltan 0 Posted April 27, 2006 i think brakeparts.co.uk do them for about 40-45 quid. Share this post Link to post Share on other sites
madspikes 41 1 Cars Posted April 27, 2006 Hummm..... Last week I was very luckly, my M/C suffered a totally failure while I was driving! It came without any real warning, apart from the following.... Which sounds very simular to the problems your having, but may or may not be related. A month or so ago I notice than the pedal would slowly progress to the floor. Basically on the way to work there is a long step hill which is often backed up with traffic. I normally coast, with my foot resting on the brakes just to control the speed. One morning I notice that the pedal was getting closer to the floor, but on replying the brakes the pedal was back to normal. It just seemed to slowly sink over time (1 to 2 mins). At the time I couldnt decide if it was the M/C or servo, and I'm still not totally sure, as I havent driven the car since changing the M/C. Just thought you should know. Having the brakes totally fail ISNT my idea of a good morning out. Mad. Share this post Link to post Share on other sites
16v205 9 Posted April 28, 2006 Cheers, thats what I was sort of hoping to hear as ive been through the complete braking system and not found a thing wrong apart from a second suspect m/c. Ill see if peugeot to a repair kit, if not ill have to fork out for another new m/c. Just wanted some reasurance that im not being stupid replacing the m/c for the second time on the same fault lol Rich Share this post Link to post Share on other sites
Guest CB-Dave Posted April 30, 2006 does the servo harden up when you pump the pedal with the engine off? Share this post Link to post Share on other sites
saml666 0 Posted May 1, 2006 I've had various components (2nd hand) fail in what seem like mysteriously coincidental ways before for reasons like rubber seals don't like drying out - these days more breakers strip the parts and clean them so you buy off the shelf, its all very well but once off the car they can dry up and so seals fail more regularly I ruined a "known good" water pump a few years back just by storing it dry, as soon as I started the engine the dry seals failed. Now I keep them in a bucket of water if rebuilding etc So yeah, maybe two failing in a row isn't so unlikely afterall? Sam Share this post Link to post Share on other sites
