ZR-1 Net Registry Forums - View Single Post - Intermittent brake feel - sometimes firm, sometimes feels very soft

WB9MCW · 08-10-2014

Time for a new/rebuilt MC.
I had the spongy deal and did a bleed on all 4 lines only to have the spongy come back in no time at all (less than 15 days - only two times out for countryside drives). It was the MC pumping air back in the system from bad seals. One wonders how this happens in a closed loop system but it just does. Every time you stab the pedal more air gets into the lines and soon the spongy pedal returns.

So I bought a used MC from a Vette Salvage Yard and sent it in on/to Rock Auto rebuild deal. Got it back and had my Mech swap it out.

Rebuild works great and I now still have my old one for a spare core in case I ever have to do it again.

I did it this way so I did not have any down time.
It takes about a week for the rebuild center to turn the MC around plus to and back from shipping time. So about 2 weeks total.

If you are doing the work yourself and have the garage space then you don't have to do the way I did. I just could not clog up my mech/buddy's shop for all that time. It is nice that my best friend is my mech as well. LOL

The company Rock Auto uses for the rebuild does excellent work. Rock has the best price and you ship direct to the rebuild company. Rock sends you all the details after you do the online purchase of the rebuild service from them.

It sure is nice to have a full firm pedal the way it should be and no fear of the dreaded spongy pedal anymore.

Here is the thread I posted on the forum. There is even an upgrade solution available now as posted in the thread.
http://zr1.net/forum/showthread.php?...brake+cylinder

08-10-2014	#2
WB9MCW Join Date: Dec 2003 Location: McHenry, Il. Posts: 6,584	Re: Intermittent brake feel - sometimes firm, sometimes feels very soft Time for a new/rebuilt MC. I had the spongy deal and did a bleed on all 4 lines only to have the spongy come back in no time at all (less than 15 days - only two times out for countryside drives). It was the MC pumping air back in the system from bad seals. One wonders how this happens in a closed loop system but it just does. Every time you stab the pedal more air gets into the lines and soon the spongy pedal returns. So I bought a used MC from a Vette Salvage Yard and sent it in on/to Rock Auto rebuild deal. Got it back and had my Mech swap it out. Rebuild works great and I now still have my old one for a spare core in case I ever have to do it again. I did it this way so I did not have any down time. It takes about a week for the rebuild center to turn the MC around plus to and back from shipping time. So about 2 weeks total. If you are doing the work yourself and have the garage space then you don't have to do the way I did. I just could not clog up my mech/buddy's shop for all that time. It is nice that my best friend is my mech as well. LOL The company Rock Auto uses for the rebuild does excellent work. Rock has the best price and you ship direct to the rebuild company. Rock sends you all the details after you do the online purchase of the rebuild service from them. It sure is nice to have a full firm pedal the way it should be and no fear of the dreaded spongy pedal anymore. Here is the thread I posted on the forum. There is even an upgrade solution available now as posted in the thread. http://zr1.net/forum/showthread.php?...brake+cylinder Last edited by WB9MCW; 08-10-2014 at 05:17 AM.