M35A2 Brake System Replacement

[Nibac]

I’m doing a total brake system replacement on a M35A2 including master cylinder with remote reservoir, shoes, springs, rubber hoses at the wheels along with bearings and seals. My question is what about the 5/16” steel tubing. Would it be recommended to replace this also…??? Thank you.

 

[frank8003]

I always wondered if there be an "overpressure test" for all the steel brakelines and how I could go about that.It all must work proper when you done
Replace it all, depends on how you value things.

Replacement of all the tubing is quite time consuming and expensive but probalby worth it. The truck is like 50 years old, what do you think? Brakes Not necessary but Crucial
Do some at a time and test I had placed .MOV on the Youtube
Heck if I can find it

 

[frank8003]

 

[Nibac]

I’m looking at the photo showing the misalignment of the adjustment cam against the shoe, mine is the same and I had one so misaligned that the cam slipped to the inside of the shoe and that adjustment was lost. I’m thinking of welding a piece on the inside of the show to give the cam a positive surface on which to ride. Anybody else have this situation…???

 

[NY Tom]

I am still in the process of doing the same job you are. I went ahead and used new line throughout. Lots of work as stated by Frank. I think it was worth it. Definitely found rust in areas of the steel tubing and inside the wheel cylinders. I used the cunifer tubing and it was pretty easy to work with. While in there I also rebuilt the air pack. Not hard stuff just time consuming. You will be surprised what the design uses to secure the tubing to the frame rails in places. Ended up pulling off the spare tire carrier and removing the air tanks just to get the old stuff out. Then cleaning and painting everything. Once you get that deep....

 

[Nibac]

Wow...you sound like me...thanks for your response...

 

[NY Tom]

Yeah no problem - if you run into any problems or have questions I can do my best to help.

 

[Nibac]

Does anyone know why the factory runs the 5/16” brake line on the left side of the frame forward, then across the frame to the right side and then forward to the front axle where it splits to the front wheel cylinders?

It looks much easier to stay on the left side of the frame all the way to the front axle and split there.

Your comments and suggestions are welcomed…

 

[Crazyguyla]

Does anyone know why the factory runs the 5/16” brake line on the left side of the frame forward, then across the frame to the right side and then forward to the front axle where it splits to the front wheel cylinders?

It looks much easier to stay on the left side of the frame all the way to the front axle and split there.

Your comments and suggestions are welcomed…

I have a M45 chassis that has the forward brake line run all the way forward and across the front cross member, then splits to the front axle. My truck being a gasser, i would surmise they change was made with the multi-fuel engine.

 

[Nibac]

I have a M45 chassis that has the forward brake line run all the way forward and across the front cross member, then splits to the front axle. My truck being a gasser, i would surmise they change was made with the multi-fuel engine.

I looks like the thinking was to make the front 5/16" line longer to match the length of the line going to the rear...but why...???

 

[Floridianson]

If it was to match my guess you never want the front coming in stronger than the rear. I much rather have the rears lock up but not the front so I do not loose steering. Yea front has a big percentage of stopping but if you can not steer could be worse. Some of the older bigger trucks had a front brake limiter to drop the percentage in the front for bad weather / snow and such. Myself years ago when using my triaxle dump in winter would adjust the slack adjuster looser in the front than the rear. Also drove slower and did not worry about stopping just skidding.

 

[NY Tom]

Maybe for ease of manufacturing? Cutting more lengths of tubing to the same size is cheaper than making more pcs. of different length. Also less to keep in stock for depot supply of spare parts. It seems a lot of this truck was built that way - which makes sense. Also might be enough stuff in the way on the left side with the fuel connections and compressor plumbing. So maybe having it on the other side there is less going on.