should i change my rear brakes over to spring brakes, i have single chambers now and the icc valve with the johnson bar. i want to do what is safest and best. 1961 4106. has any one done this change pros and cons thanks in advance. george
George, were you thinking having this done by a shop or as a DIY project? (Cost vs. a lot of plumbing, I would expect.)
Don
i was going to do it myself
I have a MCI 5C and spring brakes will NOT fit. The chambers are to big, I was looking at 30/30 spring brakes. Tom Y
from what i have read they use 30\30 chambers called mini max, the mounts have to be relocated also on the 4106
I have spring brakes on my 1961 4106 but they were on when i purchased it from Alan Baker. They work good and will slide the tires. Larry
I have the double chambered spring brake on my 62-06, required a 2.5 inch offset slack adjuster which is commonly available at most truck brake stores.>>>Dan
did you have to relocate the mounts or just use the offset slack adjuster?
I cut the slacks in half and offset them myself, then adjusted the actuator rods to the right length, works great.>>>Dan
Has anyone tried installing 24/24 on a MCI 5A? I would like to install spring brakes instead of the DD3.
dan can you give me more info on what you mean that you cut the slacks in half? i want to do this swap and trying to get as much info as i can.i read in previous post that the chamber mounts had to be relocated. what chambers did you use?part numbers? thanks george
George -
Tom Caffery has done this swap on his 4106, I'm sure he will chime in here when he sees the thread.
But, for standard, off-the-shelf truck spring brakes to be installed, you have to cut off and reposition the brake can mounting points.
Can you weld?
If not, you're going to have trouble finding a welding shop that will do the work - liability reasons, mostly.
OTOH, if you're not to far from Chaz, I'm sure he can take care of you, and you'd get to visit with another busnut in the process. . .
FWIW & HTH. . .
;)
Well, I can't say as I have ANY idea of what a spring brake is or what to do. ??? ??? ??? I'd be glad to help if I can, but I'd have to know what the situation is.
Is the parent material mild steel, cast, spring steel, etc? Is it a small part that needs to be TIG-ed or would a MIG or arc welder do?
Keep me in the loop if you want.
Chaz
p.s. George, ya ought to put your town (or even are of the country) in your personal info. It kinda helps at times.
Quote from: lloyd on November 21, 2007, 07:53:48 AM
Has anyone tried installing 24/24 on a MCI 5A? I would like to install spring brakes instead of the DD3.
The number indicates size of the brake chamber in square inches of surface area the air pressure acts on. As a result, the higher the number, the higher force applied to the brakes for a given application pressure.
If you replaced 30's with 24's, you would be reducing your braking ability by 20%. :(
There are worse things in life than DD3's. ;)
my bus does not have the dd3 chambers they are single chambers. i think later year models went to the dd3s
George, as soon as I get back this week end from a trip I'll look for the pot numbers, by cutting in half I mean I used an abrasive saw and cut them cross wise, then useing a 1/2 inch thick by 3 cold rolled tab I off set them to line up with the newly mounted pot push rods and clevises, welded them up with low hydrogen rod for strength. They have been working great for ten years, I found several years later that the offsets were available across the counter.>>>Dan
dan did you also have to relocate the pot mounts?
We had our spring brakes installed by Southern Oregon Diesel about six years ago. I don't know if they will do the alteration anymore.
The mounting pads for the original cans were cut off of the air beams and the air beams notched just enough to allow remounting of the pads; they got one of them 1 1/2" and the other one 1 3/4" closer to the axle. Both cans use the original slack adjusters and either one can be removed from it's mount without disassembly of the can.
This left an inch or so of clearance between the cans and the bulkhead. They have always worked perfectly.
It's important to get the mount strong enough; 30 inches times 125 psi is a bit less than two tons of force, so the welding needs to be able to handle a suitable safety factor. I think that 6 to 1 is a good target, so make the bracket weld capable of standing 12 tons of force.
Also, be sure to get the air supply from the brake side of the system, not the auxiliary side. The brakes have to be able to work with an air line ripped off of the suspension, etc.
For what it's worth.
Tom Caffrey
I like mine. It is a tight fit.
barn owl did you have to relocate the mounts?
I like Relocating to Spring Break!
Maybe I'll go with BK this year!
(Can I Bryce, Can I? hunh, Please, Please, Please?)
Dallas Dallas Dallas..We're talked about Buses, not getting BUSTED. :D
Besides, from what I hear, you are the "Cat's" meow anyway. ::) Wish I had a woman like that. (Does Cat have a sister, say in the 20-40 range? I have family down in TN, so a "visit" might be in order...LOL) Tell ya what; I'll apply for BK's "School of Instruction" about Spring Break and maybe learn a thing or two about "DD3's" while I'm at it.
By the way, I thought spring brakes were standard on most of the GMC's. I was considering a 4905 several years ago (before I became poor). I guess I didn't know what I was looking at. (Now that I've joined the boards, I'm learning so much more). :)
Doug
Quotebarn owl did you have to relocate the mounts?
PO had the mod done. I wish I could be of more help. I like them and think it would be worth the trouble to make the changeover. Whoever did the work did a good job. I cannot tell there was a mount change if there was one. I will look closer the next time I am under it.
Laryn
Dallas,
I know what two of the three got for a graduation present!.. ;)
For those of you that have switched to spring brakes did you also install a SR1 valve and a DC4 valve and where did you mount the extra air tank? Barn owl could I get you to take a pic from bottom up or top down?
Erik
Erik,
I will take as many pics as you need. If it's not raining I will get up under it this weekend. Let me know what you are looking for.
Laryn
I WOuld also like to know how the air is routed as compared to the original system? were does the button on the dash lines go ect? thanks george
I am looking for where the brake pot mount is welded to the suspension. Are the chambers 30/30?
Thanks Erik
:( I didn't forget about you guys. Went out for some Christmas shopping and as always it took longer than planned. I will be under the bus soon because I am replacing the Sheppard steering box and the pump. My father is picking them up from NIMCO next week for me.
Nearly everything you need to know is here:
http://www.bendixvrc.com/itemDisplay.asp?documentID=4631
Len