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73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: TxFiddler on June 02, 2011, 05:38:19 pm

Title: Brake Question
Post by: TxFiddler on June 02, 2011, 05:38:19 pm
So, I'm almost back on the road after adding the 427 and 700R4.  Started to bleed the brake system yesterday and noticed that there is NO fluid going to the rear lines.  New master cylinder installed and the lines were taped off during the swap.  I did clean the proportioning valve while everything was apart for the swap.  Could the proportioning valve be the culprit.  Rear brakes are standard drum with new lines on the rear axle.  Front are Wilwood D52's.  I am getting fluid to the front calipers ok but just not to the rear cylinders.  I know that someone out there knows what the problem is.
Thanks in advance,
Fidd
Title: Re: Brake Question
Post by: 1979C20 on June 02, 2011, 05:48:12 pm
Did you bench bleed the master cylinder?
Title: Re: Brake Question
Post by: Irish_Alley on June 02, 2011, 05:54:38 pm
is you did bench the system then try remove the line before the p valve then see if fluid comes out remove the valve after and see
Title: Re: Brake Question
Post by: TxFiddler on June 02, 2011, 06:08:22 pm
Yes, the master was bench bled.  So, if I'm getting fluid to the front calipers, frome the p valve but no fluid after the p valve, the problem must be the p valve.  Correct?
Title: Re: Brake Question
Post by: Irish_Alley on June 02, 2011, 06:16:08 pm
dont work with the front but work on the rear since thats where the problem is
Title: Re: Brake Question
Post by: TxFiddler on June 03, 2011, 04:30:38 pm
This morning before work, I took the lines off the master cylinder and put the plugs in.  I removed the lines and blew air through them.  I then removed the proportioning valve, sprayed with brake clean and blew air through it.  Seems to not be clogged.  I then disconnected the rear brake lines at the rear wheels and aimed them toward the back of the truck.  I then put brake clean in the line and blew it out with the compressor.  Some dirty old fluid came out.  Since the p valve flows with air, I guess the problem could have been some crud in the rear lines.  Gonna reassemble Saturday evening and see whats up.  Also, can I remove the master cylinder, drain it and bench bleed all over again just to be on the safe side?
Thanks,
Fidd