4 wheel drum brake balance. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ChevyBrad · 01-02-2016, 10:06 AM

Hey guys, I have a 3800 1 ton single rear wheel with factory original front axle and brakes that I swapped a rear dana 60 full floater axle from a 77 F250 into a little while ago. I drove the truck around for one summer and noticed I had issues with maintaining proper brake balance, front to back. I have a dual master cylinder and I had originally installed a manual proportioning valve in the rear line to reduce the pressure but, the problem is that the front brakes are manual adjustment while the rear is automatic. I found that as I drove the truck, the front brakes would wear slightly and then the rears would start wanting to lock up first in the rain. I could tighten the proportioning valve then to keep driving until I adjusted the front again but, that's not a fix. Anybody have any ideas or tried to run a similar set up before? I was considering trying to make the rear manual adjustment as well but I do not think I can. Would an automatic proportioning valve work by delaying the rear brake application until after the fronts started working? Does anyone know if I could convert my rear dana 60 to manual adjustment as well so everything backs off at the same rate? Thanks.

dwcsr · 01-02-2016, 12:10 PM

That's one of the issues with mixing old brakes with new self adjusters. Bias isn't the issue its adjustment.. It may also depend on the master, is it a straight bore or a step bore. Step bore has a different bore size for the front and back. Converting to Disc would help solve the adjustment issues and greatly help with bias. Converting back to manual would require replacing the adjusters and removing the arm. You can't just remove the arm the adjuster will back off. it needs the spring over top of it.

ChevyBrad · 01-02-2016, 12:51 PM

I do believe its a straight bore. Yes, disks would definitely fix the whole issue but, for now I'm trying to keep it as stock looking as I can. I have the rear end apart right now, putting in new gears/posi. So you can get manual adjusters? I tried to see if removing the cable would work and just leaving the arm on but, the spring on the arm will not hold it into the adjuster without the cable tension. Converting the rear axle to manual adjustment would fix the whole problem in my opinion. Thanks.

dwcsr · 01-02-2016, 01:31 PM

You will have to get parts from a pre 67 ford F250 with a dana 60 to get the parts to eliminate the self adjusters. I would try that first.

Here is a picture of what a disc kit on the 1 ton looks like. You barely see the caliper and the rotor is covered.

**mr48chev** · 01-02-2016, 03:33 PM

If you have Bendix brakes on the front you might be able to get adjusters for a later model and put them on without a lot of hassle. You still have to back up a lot to work the adjusters though.

ChevyBrad · 01-03-2016, 12:24 PM

Thanks for the responses guys. I will definitely look into the pre- '67 adjusters. That will fix all the issues I have been working through. I don't mind adjusting brakes, I just didn't want to have to do it ever couple days of hard driving ha. I am going to try the drums first because they were just rebuilt before I started the rebuild on the truck but, those disk brakes do look good on there. If I decide to do the conversion, I will definitely be looking into you guys and dwscr, you did a great job on that one ton restoration! I had not heard of your parts company before but will definitely be shopping there now as well. Thanks again, Brad.

01-02-2016, 10:06 AM	#1
ChevyBrad Registered User Join Date: Mar 2013 Location: Buffalo, New York Posts: 61	4 wheel drum brake balance. Hey guys, I have a 3800 1 ton single rear wheel with factory original front axle and brakes that I swapped a rear dana 60 full floater axle from a 77 F250 into a little while ago. I drove the truck around for one summer and noticed I had issues with maintaining proper brake balance, front to back. I have a dual master cylinder and I had originally installed a manual proportioning valve in the rear line to reduce the pressure but, the problem is that the front brakes are manual adjustment while the rear is automatic. I found that as I drove the truck, the front brakes would wear slightly and then the rears would start wanting to lock up first in the rain. I could tighten the proportioning valve then to keep driving until I adjusted the front again but, that's not a fix. Anybody have any ideas or tried to run a similar set up before? I was considering trying to make the rear manual adjustment as well but I do not think I can. Would an automatic proportioning valve work by delaying the rear brake application until after the fronts started working? Does anyone know if I could convert my rear dana 60 to manual adjustment as well so everything backs off at the same rate? Thanks.

01-02-2016, 12:10 PM	#2
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Re: 4 wheel drum brake balance. That's one of the issues with mixing old brakes with new self adjusters. Bias isn't the issue its adjustment.. It may also depend on the master, is it a straight bore or a step bore. Step bore has a different bore size for the front and back. Converting to Disc would help solve the adjustment issues and greatly help with bias. Converting back to manual would require replacing the adjusters and removing the arm. You can't just remove the arm the adjuster will back off. it needs the spring over top of it.

01-02-2016, 12:51 PM	#3
ChevyBrad Registered User Join Date: Mar 2013 Location: Buffalo, New York Posts: 61	Re: 4 wheel drum brake balance. I do believe its a straight bore. Yes, disks would definitely fix the whole issue but, for now I'm trying to keep it as stock looking as I can. I have the rear end apart right now, putting in new gears/posi. So you can get manual adjusters? I tried to see if removing the cable would work and just leaving the arm on but, the spring on the arm will not hold it into the adjuster without the cable tension. Converting the rear axle to manual adjustment would fix the whole problem in my opinion. Thanks.

01-02-2016, 01:31 PM	#4
dwcsr Hollister Road Co. Join Date: Apr 2005 Location: Houston Posts: 6,131	Re: 4 wheel drum brake balance. You will have to get parts from a pre 67 ford F250 with a dana 60 to get the parts to eliminate the self adjusters. I would try that first. Here is a picture of what a disc kit on the 1 ton looks like. You barely see the caliper and the rotor is covered. Attached Images

01-02-2016, 03:33 PM	#5
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,711	Re: 4 wheel drum brake balance. If you have Bendix brakes on the front you might be able to get adjusters for a later model and put them on without a lot of hassle. You still have to back up a lot to work the adjusters though. __________________ Founding member of the too many projects, too little time and money club. My ongoing truck projects: 48 Chev 3100 that will run a 292 Six. 71 GMC 2500 that is getting a Cad 500 transplant. 77 C 30 dualie, 454, 4 speed with a 10 foot flatbed and hoist. It does the heavy work and hauls the projects around.

01-03-2016, 12:24 PM	#6
ChevyBrad Registered User Join Date: Mar 2013 Location: Buffalo, New York Posts: 61	Re: 4 wheel drum brake balance. Thanks for the responses guys. I will definitely look into the pre- '67 adjusters. That will fix all the issues I have been working through. I don't mind adjusting brakes, I just didn't want to have to do it ever couple days of hard driving ha. I am going to try the drums first because they were just rebuilt before I started the rebuild on the truck but, those disk brakes do look good on there. If I decide to do the conversion, I will definitely be looking into you guys and dwscr, you did a great job on that one ton restoration! I had not heard of your parts company before but will definitely be shopping there now as well. Thanks again, Brad.



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