Bench bleeding a master cylinder

[hemi68charger]

OK.. I'm not going nuts here.... But, when one bench bleeds a master cylinder, one should get a fluid pulse with each compression of the piston, no? I just got through trying to install and bleed the brakes on my 500. I just got through replacing ALL the fluid lines, rebuilding the calibers and getting new wheel cylinders. Easy enough and not rocket-science. I got a new master cylinder (Cardone) and installed it. I got my bleeder lines attached to the master cylinder prior to installing to the main lines. The bleeder lines are nothing more than former main lines I cut and bent back into the forward and rear reservoirs. Pushing the pedal, everything seemed to be ok. I could see bubbles coming up through the fluid in the reservoirs like it is supposed to do.. Great, I hook up the lines and start pumping (right rear is the one with the bleeder screw lose with tube into a jar of brake fluid). As I pump, the rear reservoir of the master cylinder was draining (as one would expect with fluid filling up the lines and caliper). Ok,, front calipers seem to be tight, no problem and the fluid level is lower, I replaced depleted fluid. The front reservoir on the other hand doesn't drain at all..... GREAT !!!!!  Nothing's going out the rear right, no air or anything. I disconnect the main fluid lines into the master cylinder to see if fluid would squirt out. Welllllll, the rear reservoir orifice squirts fluid, but the front?... Nada... Nothing........ LORDY !!!  OK, so, I SHOULD get fluid discharge from both orifices when pumped through full motion, no? Looks like I have a defective CARDONE master cylinder AGAIN !!!!


No?

Thanks...

[1969chargerrtse]

" OK, so, I SHOULD get fluid discharge from both orifices when pumped through full motion, no? "  You'd certainly think so?  Yes you should.

[Back N Black]

 Try gravity bleeding the system. open all four bleeders and let bleed, should take about a hour. Make sure the reservoir is full.

[tan top]

when i bench bleed master cylinders , i connect a syringe to each   bleeder pipe inturn , & draw the fluid through , once done that a couple of times , bend the bleeder lines back in the reservoir & bench bleed in normal way , but i always , push the piston just enough to do the front , then once no bubbles carry on  , full stroke to do the rears , give the piston time to fully retract  , i normally  push piston , let it retract , the count  10 seconds & repeat  until all bubbles are gone  , make sure master cylinder  is level on the bench vice , i normally jack the bench up , while putting a spirit level on the top of the master cylinder to get it level

the above  is what i do now , after getting two  raybestos  & a cardone one  MC , not bleeding ,  i'm sure its quality  control with these makes , 
must of bled 100s of new  master cylinders when working on customers cars  , never had a prob 

[hemi68charger]

when i bench bleed master cylinders , i connect a syringe to each   bleeder pipe inturn , & draw the fluid through , once done that a couple of times , bend the bleeder lines back in the reservoir & bench bleed in normal way , but i always , push the piston just enough to do the front , then once no bubbles carry on  , full stroke to do the rears , give the piston time to fully retract  , i normally  push piston , let it retract , the count  10 seconds & repeat  until all bubbles are gone  , make sure master cylinder  is level on the bench vice , i normally jack the bench up , while putting a spirit level on the top of the master cylinder to get it level

the above  is what i do now , after getting two  raybestos  & a cardone one  MC , not bleeding ,  i'm sure its quality  control with these makes , 
must of bled 100s of new  master cylinders when working on customers cars  , never had a prob 

This is typically how I bench bleed my master cylinder.... I believe the dang seals are leaking within the piston. I've done plenty of brakes in my days and I'm starting to thing every dang Cardone master cylinder is a piece of junk.... I went through 4 MC's on my Daytona and eventually just rebuilt/resealed original one (it worked perfect). Unlikely, I don't have luxury with the 500....

[tan top]

 was thinking the same sort of thing  Troy ,  my thinking ,  was - is - maybe ,  if who ever builds these master cylinders  for cardon  , raybestos , when they fit  the piston with new seals  , they don't dunc them in brake fluid , coupled with a fresh honed , machined bore , first stroke  tears the seals up , that was my thinking  draw the fluid through first with a syringe     ,

[gtx6970]

The way I do it is, put fluid in the master cylinder( on the bench vise ) and just let is sit open( no cap and no lines on the unit )  to drain a bit. like mentioned it lubes the internal seals just a bit , ( knocks on wood) never had a problem in 30 years

[resq302]

Troy,

I have to agree that it seems like A1 cardone anymore is called a "spray and pray" job.  The throw a seal kit in it, spray it up all nice and pretty, and pray that it works.  I've found that unless you get a brand new one like NAPA made a couple years ago, they either don't work or will start leaking fairly soon unless you go through a good company that will sleeve the cylinder and then rebuild it.  With parts such as these, especially the disc brake stuff, I try to get spares and keep them on hand since a lot of the parts stores don't carry them or would take at least a couple days to get in.  I always try to be prepared, but the funny thing is, I was never a boy scout who's motto that is.