Brake Master Cylinder & spongy brakes

=jsy= $H466Y

Guest
Having recently changed my master cylinder and subsequently having to replace the primary brake pipe to the ABS modulator, then bleeding all brakes until there is no air at all coming out using both an Eezibleed kit and the conventional 2 person method - I took the car for a drive at all speeds and am getting nothing but a spongy brake pedal. The pedal is fine when pumped a couple of times initially but if pumped and held down the pedal goes to the floor with a little force. I drove down a country road with no other cars about at approx 50mph and slammed on the brakes hard and it emergency stopped with no problem. As the brake pedal goes to the floor and its only the last bit that really makes any difference it was pulling to the right a very small amount for this small time. I thought this would be down to one brake having air left in so I rebled the brakes but to no avail. Any ideas.
 

danfr

Active Member
Sep 13, 2007
49
0
horsham
sounds like the master cylinder wasnt properly bench bled before installing it.
have you tried bleeding it from the nipple at the end of the MC in situe?
its amazing what a difference even a tiny amount of air can make in there
 

gcooper

Guest
spongy brakes

I'm having the exact same problems. I have had a new brake master cylinder, new servo, brakes bled properly twice,and checked for leaks. But the brake pedal is still spongy and you can push your foot through to the floor. Any advice from anyone would be really appreciated as I,M due to take my family to cornwall next week. Thanks
 

andycupra

status subject to change
i know of someone that had the same issue, dealer fitted new master cylinder bled it many times, and didnt solve it.

Ive seen many threads of similair content and as yet no fixes.

He did say one day that the peddle 'clonked' and was ok for 2 days, then was the same again.
Anyone know if there is adjustment on the pedal?
 

hopper

Full Member
May 7, 2005
163
0
stoke-on-trent
weve had this at work before and it needs the abs pump to be operated whilst bleeding brakes, we go a bosch diagnostic machine which we use when bleeding if problems occur
 

=jsy= $H466Y

Guest
It turned out that I still had air left in the system as I eventually took it to a garage to get it on a lift and it took no more than 10 mins. the air was in the rear offside pipe apparently
 

Fl@pper

Back older greyer and less oilier but always hope
Jun 19, 2001
12,370
26
Gloucester
so it was just a case of doign the bleed properly then?

usually is but no matter how many times done and no air out all done proper they are a nightmare to get all of it out

once saw 3 guys on a first attempt on a toledo V5 with the 5051 machine going take 7 hours and 30L of fluid to get it sorted :p
 
Feb 1, 2007
1,602
1
Nottingham
As dan fr said the air usually hides in the master cylinder.
Always bleed the cylinder when having worked on the brakes particularly a brake fluid change.
Glynn
 

=jsy= $H466Y

Guest
for me yes - cheesed me off when I thought that I had just changed the brake pipes and master cylinder only to be scuppered by that. it wasnt much air probably a couple of inches in the pipe.
 
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