Help I can bleed my new brakes system - The 1947 - Present Chevrolet & GMC Truck Message Board Network

JayDubBlazer · 09-28-2008, 09:10 PM

I've replaced everything in the system, the lines, MC, wheel cylinder, calipers, booster. I am having trouble bleeding the rear brakes. I am on the second master cylinder and have bench bleed it, and then bleed it through the proportioning valve. When I try to bleed the system the air in the plastic drain tube just move back and forth, but never disapate.

Any help would be apprieciated, thanks

68C15 · 09-28-2008, 09:34 PM

start at the top and work your way back/down. with each part disconnected have a buddy SLOWLY pump the pedal while you hold your finger loosley over the line/bleeder. kind of acting as a check valve. after each part has fluid flowing connect it and move down the line. at this time you are not looking for perfection, just a flow. once this is done then you can go back and do the traditional bleed procedure.
LF, RF, RR, LR. the reason I say RR before LR is the hose is on the pass. side.

JayDubBlazer · 09-29-2008, 07:35 AM

We went through and bleed it from each connection, but for some reason we can not get the back to bleed properly, is there some brake pedal adjustments that I need to make? I have a lower profile booster

cdowns · 09-29-2008, 08:04 AM

have you clamped the pin on the combo valye like it says to do in the manual?

68C15 · 09-29-2008, 09:15 PM

Quote:

Originally Posted by cdowns

have you clamped the pin on the combo valye like it says to do in the manual?

BINGO!!!!!

the combination valve shuts off flow to which ever side it see no resistance.

JayDubBlazer · 09-30-2008, 07:51 AM

Quote:

Originally Posted by cdowns

have you clamped the pin on the combo valye like it says to do in the manual?

No, i didn't, In hindsite i don't believe they gave me a manual on the valve. That i did solve a lot of the problems. I was able to bleed the system through the valve. I gravity feed the rear line, I was able to get fluid to the left rear but not the right rear. I was even able to bleed the left rear. There must be something stuck in the right line between the rear spliter and the right drum piston. So far this two hour job has taken me about 16 man hours, geesh, good thing I didn't bid this as a lump sum.

JayDubBlazer · 10-10-2008, 03:05 PM

I am still having trouble bleeding my brakes. I have clamped the combo valve to no avail. I am now getting fluid to seep out of the front right, squirt out of th rear left, do nothing on the rear right and occasionly squirt out of the front left. It actually started to build a litter pressure this morning but somehow it all disappeared. Is it possible that I got a bad wheel cylinder on the rear left brake. I really coming to my wits end here, I don't think this should be that hard. I have gone through and retightened all the connections, there are no leaks. I am on my second master, from what I can tell I am getting proper movement on the my brake. What am I missing? Faulty combo valve? the pin is leaking just a little bit, is that common. Did I tighten the clamp down to much and damaged something.

Sorry for the rumbling but I just can't seem to get this whipped.

JayDubBlazer · 10-11-2008, 02:52 PM

Well my rear right wheel cylinder is blown, I have replaced that and have been able to bleed the rear. I am still getting a ton of air in the front brakes. More air than the lines could possilble hold. The proportioning valve is leaking and I think I am taking on air from there. Is this possible. I am going to see if the autoparts store cares these in stock. Its do or die, the last nice weekend of the year.

JayDubBlazer · 10-13-2008, 03:38 PM

Just an update to everyone, the problem with the front brakes was the proportioning valve. The pin on the old one was seaping fluid and sucking air back in when the brake was released. I went to the juck yard, found a good one, paid five bucks and wala. I have a stoppable truck. Is it possible that I ruined the prop valve when I clamped it to hard? I was wondering if something could have broken because the back wheel cylinder wasn't actuating and not giving any "give" to the system.

Thanks

72BLUZ · 10-13-2008, 07:25 PM

start at the right rear and open the bleeder screw and let it run for about 30 minutes. close it off and do the same to the driver side rear. then go to the passenger side front and do the same to the others till all are done. the procedure is called gravity bleed and you start at the futherest point from the master cylinder working your way to the closest. make sure to leave the top off the master cylinder and continually pour brake fluid in to keep air from going back into the system. adjust the drum brakes and when you are done you will be able to pump them up unless you have a restriction or a cylinder inop

cparman · 10-13-2008, 08:01 PM

back in the day, when cars were simple, ocasionally we would have been to heavy footed on the brake pedal when we bled the brakes on cars/trucks like ours. If it were me, I would do like someone suggested. gravity bleed the rear brakes for 10 minutes or so. close the bleeders off, have a long cold drink of water, and sit down in your truck, and STOMP on the brake pedal a couple of times. This will center the prop valve. another drink of water, and have someone help you bleed the brakes depressing the pedal GENTLY, and see if the volume and pressure increases in the rear brakes. ALSO, MAKE SURE that the rear brakes are adjusted properly, BEFORE, you try the above

09-28-2008, 09:10 PM	#1
JayDubBlazer go cyclones Join Date: Jun 2003 Location: Ames, IA Posts: 1,885	Help I can't bleed my new brake system I've replaced everything in the system, the lines, MC, wheel cylinder, calipers, booster. I am having trouble bleeding the rear brakes. I am on the second master cylinder and have bench bleed it, and then bleed it through the proportioning valve. When I try to bleed the system the air in the plastic drain tube just move back and forth, but never disapate. Any help would be apprieciated, thanks __________________ Wes PROJECT OLE GREEN 1972 Blazer 4X4 350/700R4 2017 Silverado LT Last edited by JayDubBlazer; 10-10-2008 at 03:04 PM. Reason: just noticed a typo in the title

09-28-2008, 09:34 PM	#2
68C15 blood type; Retumbo Join Date: Jan 2004 Location: next to my reloading bench Posts: 10,269	Re: Help I can bleed my new brakes system start at the top and work your way back/down. with each part disconnected have a buddy SLOWLY pump the pedal while you hold your finger loosley over the line/bleeder. kind of acting as a check valve. after each part has fluid flowing connect it and move down the line. at this time you are not looking for perfection, just a flow. once this is done then you can go back and do the traditional bleed procedure. LF, RF, RR, LR. the reason I say RR before LR is the hose is on the pass. side.

09-29-2008, 07:35 AM	#3
JayDubBlazer go cyclones Join Date: Jun 2003 Location: Ames, IA Posts: 1,885	Re: Help I can bleed my new brakes system We went through and bleed it from each connection, but for some reason we can not get the back to bleed properly, is there some brake pedal adjustments that I need to make? I have a lower profile booster Attached Images __________________ Wes PROJECT OLE GREEN 1972 Blazer 4X4 350/700R4 2017 Silverado LT

09-29-2008, 08:04 AM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Help I can bleed my new brakes system have you clamped the pin on the combo valye like it says to do in the manual? __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

10-10-2008, 03:05 PM	#7
JayDubBlazer go cyclones Join Date: Jun 2003 Location: Ames, IA Posts: 1,885	Re: Help I can bleed my new brakes system I am still having trouble bleeding my brakes. I have clamped the combo valve to no avail. I am now getting fluid to seep out of the front right, squirt out of th rear left, do nothing on the rear right and occasionly squirt out of the front left. It actually started to build a litter pressure this morning but somehow it all disappeared. Is it possible that I got a bad wheel cylinder on the rear left brake. I really coming to my wits end here, I don't think this should be that hard. I have gone through and retightened all the connections, there are no leaks. I am on my second master, from what I can tell I am getting proper movement on the my brake. What am I missing? Faulty combo valve? the pin is leaking just a little bit, is that common. Did I tighten the clamp down to much and damaged something. Sorry for the rumbling but I just can't seem to get this whipped. __________________ Wes PROJECT OLE GREEN 1972 Blazer 4X4 350/700R4 2017 Silverado LT

10-11-2008, 02:52 PM	#8
JayDubBlazer go cyclones Join Date: Jun 2003 Location: Ames, IA Posts: 1,885	Re: Help I can bleed my new brakes system Well my rear right wheel cylinder is blown, I have replaced that and have been able to bleed the rear. I am still getting a ton of air in the front brakes. More air than the lines could possilble hold. The proportioning valve is leaking and I think I am taking on air from there. Is this possible. I am going to see if the autoparts store cares these in stock. Its do or die, the last nice weekend of the year. __________________ Wes PROJECT OLE GREEN 1972 Blazer 4X4 350/700R4 2017 Silverado LT

10-13-2008, 03:38 PM	#9
JayDubBlazer go cyclones Join Date: Jun 2003 Location: Ames, IA Posts: 1,885	Re: Help I can bleed my new brakes system Just an update to everyone, the problem with the front brakes was the proportioning valve. The pin on the old one was seaping fluid and sucking air back in when the brake was released. I went to the juck yard, found a good one, paid five bucks and wala. I have a stoppable truck. Is it possible that I ruined the prop valve when I clamped it to hard? I was wondering if something could have broken because the back wheel cylinder wasn't actuating and not giving any "give" to the system. Thanks __________________ Wes PROJECT OLE GREEN 1972 Blazer 4X4 350/700R4 2017 Silverado LT

10-13-2008, 07:25 PM	#10
72BLUZ Registered User Join Date: Nov 2006 Location: lafayette, ga. Posts: 832	Re: Help I can bleed my new brakes system start at the right rear and open the bleeder screw and let it run for about 30 minutes. close it off and do the same to the driver side rear. then go to the passenger side front and do the same to the others till all are done. the procedure is called gravity bleed and you start at the futherest point from the master cylinder working your way to the closest. make sure to leave the top off the master cylinder and continually pour brake fluid in to keep air from going back into the system. adjust the drum brakes and when you are done you will be able to pump them up unless you have a restriction or a cylinder inop __________________ Freedom is never more than one generation away from extinction. We didn't pass it to our children in the bloodstream. It must be fought for, protected, and handed on for them to do the same.... Ronald Reagan Last edited by 72BLUZ; 10-14-2008 at 12:47 AM.

10-13-2008, 08:01 PM	#11
cparman sharp as a marble Join Date: Jan 2007 Location: atlantic beach,florida Posts: 1,082	Re: Help I can bleed my new brakes system back in the day, when cars were simple, ocasionally we would have been to heavy footed on the brake pedal when we bled the brakes on cars/trucks like ours. If it were me, I would do like someone suggested. gravity bleed the rear brakes for 10 minutes or so. close the bleeders off, have a long cold drink of water, and sit down in your truck, and STOMP on the brake pedal a couple of times. This will center the prop valve. another drink of water, and have someone help you bleed the brakes depressing the pedal GENTLY, and see if the volume and pressure increases in the rear brakes. ALSO, MAKE SURE that the rear brakes are adjusted properly, BEFORE, you try the above



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