B61T upgrade to Springbrakes

[thomastractorsvc]

Good Morning All,

I am currently convalescing from a service connected surgery and since I have a little bit of time on my hands and my wife’s laptop I was hoping to research what is required to change over the brake pods. Develop a list of parts and a straight forward thread that documents the process for the future.

I am no expert on Mack B61s brake systems but I am an ASE certified Medium/ Heavy Truck. Years ago hearing about converting a single air system over to springbrakes without adding a secondary system.

If anyone has done a similar upgrade or familiar with the process I would appreciate comments, pictures, parts used.

Thanks

[Mike]

Good Mornin,

I know that most of us on the B Models use the 24/24 cans on rear axle, if this is your setup. Also if you research in this section on BRAKES, go back to 11/23/2009 and you will find the subject for a 61 B-75 Air Brake Schematics. Hope this helps.

Regards

mike

[Rob]

Basically you need a PP1 series air valve for the dashboard, a TP3 series tractor protection valve for the rear of the cab the air hoses attach to, and E3 series foot valve for applying service brakes, and a R12 valve to actuate the spring brakes. The Bendix website or has been mentioned here is a great asset. Your choice with either 24/24, 24/30, or 30/30 spring brake chambers but 30/30 are most common and least expensive.

Rob

[Freightrain]

The size of the chamber will depend on what brackets you have. Mine would accept 30/30's, but most don't.

[JumperAndSon]

Basically you need a PP1 series air valve for the dashboard, a TP3 series tractor protection valve for the rear of the cab the air hoses attach to, and E3 series foot valve for applying service brakes, and a R12 valve to actuate the spring brakes. The Bendix website or has been mentioned here is a great asset. Your choice with either 24/24, 24/30, or 30/30 spring brake chambers but 30/30 are most common and least expensive.

Rob

Somebody told us to put "Maxies" on our B60. I guess that is the name for spring brakes that your talking about here?

Ben

[Freightrain]

Yup.

[Rob]

The size of the chamber will depend on what brackets you have. Mine would accept 30/30's, but most don't.

All of the single axle mouting arrangements I've seen have the brake cannisters just outside the differential using long "S" cams for the brakes. Not on the ends like the tandems.

Rob

[thomastractorsvc]

Retrofit Mack B61T Park Brake System.

I own a 1959 B61T Single Axle Tractor, this thread will document my process of retrofitting the rear axle to “Spring Brake” brake chambers. My truck has a single air system with only one air reservoir tank. I will not discuss air brake theory unless it is important to the retrofit.

Disclaimer- Use of this information is at your own RISK and PERIL. Obviously there is a risk of accident, incident and injury this thread is not intended to be the “end all/be all” or an all-inclusive description on retrofitting the brake / parking brake system on an antique truck or other air brake system. All information that I provide is described to the best of my ability and may contain errors or omissions that could result in an accident, incident, injury or death. There is no guarantee of the validity of the information found here or guarantees about the accuracy, completeness, or adequacy of the content of what is written or posted. Use of information is at your own risk and peril.

Mechanical Ability and Skill

General mechanical understanding of air brake system and general mechanical expertise is required. Common and basic safety considerations and installation processes must be followed. Such as the use of chock blocks, safety glasses, disconnecting of battery and consideration of pressurized air brake system.

If you do not have the required general mechanical understanding of an air brake system, general mechanical expertise that is required, doubt your skills or just prefer to have someone else perform the work, check with a qualified shop and certified mechanic to have the retrofit done.

Parts

There are numerous truck part vendors’ that are available for sourcing the required parts both locally and online. In my location it is easier for me to order online. Whatever your source for parts, confirm that the parts are DOT certified for the application they are to be utilized in.

Parts List

1. "Spring" or "Maxi-Brake" rear brake chambers – two (one for each side) WARNING: NEVER interchange 3.0" (76 mm) stroke actuator components with 2.25" (57 mm) or 2.5" (64 mm) stroke components. WARNING: NEVER interchange spring brake manufacturer’s components, although spring brake manufacturers components look similar performance and stroke may be seriously affected which could result in Injury or Death. +++Before ordering determine the length of stroke of current brake chamber

2. Tee Fitting- two (one front air supply and one for rear air split) one to be mounted under dash one near the rear cross-member, ahead of the rear axle.

3. Rubber Air Lines- two (one for each side) from the tee to the rear brake chambers, Inspect the existing air/lines hoses as now would be a good time to replace if needed.

4. Air line from Tee Fitting to interior cab position at least 3/8” also Air line from valve to air source.

5. Air valve –Push/Pull

6. Misc fittings as required

Next Order Parts and Wait

[thomastractorsvc]

Update, still waiting on parts, did get my door locks.

[Green Dash]

Sorry, I have nothing to offer.

I just want to wish you well in your recovery and see if I can learn something here.

[thomastractorsvc]

Thanks, going stir crazy though but pay now or pay worse latter.

[thomastractorsvc]

Almost got everything and got my stiches out today wont be long now!

[thomastractorsvc]

Alright got all the parts

2 30/30 Brake Chambers $58.47 ea (Short Stroke)

2 30” Rubber Brake Hose $10.61 ea

2 32” Rubber Brake Hose $10.86 ea

20 ft 3/8 Air line $1.14 per ft

1 Push Pull Valve with knob new $33.61

Miscellaneous fittings, plugs and tees $21.35

Time about 1.5 hours, probably could have done in about an hour but had to heat the old mounting nuts on the left side chamber.

1. Remove existing chambers and hoses

2. Measure length of old chamber push rods from chamber back to center of yoke, cut new rods to length. (remove yoke leave jam nut on rod and turn until it is close to chamber, this way you can chase the threads if you get a burr after you make the cut)

3. Thread on yoke and adjust to proper length

4. Mount new chambers (watch orientation to keep hose fittings to the inside)

5. Put pins in yoke to slack adjusters, (depending on your brake adjustment may have to adjust slack adjusters)

6. Mount tee fitting for Spring Brake Hoses ( I made a simple bracket to hold the Tee Fitting and welded to the bottom of my hitch plate, keep centered, as not to interfere with drive shaft and/or hoses may not reach)

7. Run air line to cab area to where you will mount your push/pull valve ( I ran mine along the existing copper lines and zipped tied, make sure to keep it away from anything that spins or gets hot)

8. Mark location for valve and mount valve. (the valve will be marked and depending on your valve will require a supply air and the delivery air line to the Spring Brakes, my valve required 1 plug, the back port on my valve is left open for discharge/vent it is not marked)

9. Select air supply line to tee into. (must have a constant air supply at all times, I tee'd in my air pressure gage to this line so I now have Air Pressure Gage and Spring Brake Valve on the same supply line)

10. (Chock wheels) connect all fittings and check for leaks, tighten as required or repair. (check for proper brake adjustment and movement)

Now you are Done, pictures to come see

If I had a tandem I would do the same except instead of using a tee I would buy a R6 or R12 valve for ease of connecting the 4 hoses for the Spring Brakes.

Edited May 4, 2012 by thomastractorsvc

[Freightrain]

Looks good. Bet it's nice knowing that when you park the truck now, it will DEFINITELY be there when you come back. Unlike the old drum parking brakes/wood chock LOL!!

[thomastractorsvc]

So true, I changed the yoke and rod on the old park brake but no luck, plenty of "meat" but no holding power, it is easier to do the spring brake set up then mess around with new shoes and disassembly of the old drum brake, just glazed I am sure, but money and time wise I am sure it would be more, had about $30 in the rod and yoke.

[39 Baby Mack]

I know this is a little late because you have the job all done and it looks great.

I do have one suggestion, if you notice when you set the spring brakes they might seem to set a little slow

this is because the air has to exhaust all the way up through the push-pull valve under the dash before they will set.

If you replace the tee fitting on the emergency side with a Bendix QR-1 quick release valve or equivalent the parking brakes will set much quicker

and you won't hear so much air leaking out from under the dash when you set them.

Just a suggestion, this is the way i used to plumb them up.

Ron

[Maddog13407]

yup, i agree. this is the way i plumbed mine up. only difference is i used a quick release valve with a check valve in it so if you have you foot hard on the brake pedal, i dont think the spring brakes will apply. least this is the way the guy at the counter explained it.

[39 Baby Mack]

The check valve is already built into the quick release valve, that's how they work.

Ron

[Maddog13407]

the quick release valve i bought has a 4th port on the back side where you T into the original quick release valve and run an air line from the service brakes to the port. dont really get it but thats how the diagram is and it works.

[39 Baby Mack]

I don't think I've ever seen one of those, just used the old fashioned B&W QR-1 valves and Midlands that are similar.

Ron

[thomastractorsvc]

Still working on her so not out driving yet and parking at the truck stop, in the yard around the shop seems to set pretty quick

[doubleclutchinweasel]

Nice job.

I just did some similar work on my R600, which originally had DD3 chambers. Looks like we may have used the same brand of chambers. Looks like the ones from Ranger Brake in Tennessee. I got mine from CarQuest. Talked to the son of the founder of the company. Pretty cool little family business. They made components for other brake folks for years, and then started selling their own. They still sell to the other guys from time to time, And, I liked the price!

I didn't notice how you handled the anti-compounding function (sorry). My truck had a PP-2 control valve instead of a PP-1. This valve has built-in anti-compounding capability, via a line tee'd off the service brake line. It is the one attached to the lower part of the valve. Of course, you may have handled this a dozen different way. If so, sorry for the distraction.

I used a Haldex-Midland-remanufactured Bendix QR-1 as a quick release valve, as well as a convenient place to tee the lines.

I still have LOTS of lines to upgrade!

Keep up the good work.

Kent