Brake issue…what would you do?

[DaneGer21]

Ok, let me start by saying my truck has ZERO pedal for braking. Most of you reading this know I just got my truck running the other day. The brakes are the next thing on the list that need repaired.(I do know I have one bad air tank, I have a new one in route and that will be replaced first)

Anyways my question is, Would you start at the beginning of the brake system(master cylinder) or at the end(wheel cylinders, shoes, etc)?

Or should I just plan on going through EVERYTHING?

Any thoughts? Or experience as to where to start, or any certain things that are just common issues and where to look.

Thanks!

***For the record, I have NOT inspected or looked at ANYTHING brake related yet***

 

[98G]

Replace tank, determine nature of fluid and top off, bleed the brakes, see what you've got at the that point.

Inspect everything, starting at the master cylinder.

This is what I'd do.

 

[frank8003]

Set up to put shop air into the right rear glandhand.
One can find all the leaks quietly without Deuce engine running.

When I made adapters they were multi functional, so... NOT like me.
I like to be able to attach anything to anything, You just need an air input and maybe 3 fittins.
110 Psi and much, much less is all one would ever need. Try 30psig.

 

[Bill Nutting]

I did something similar. I carry an air hose on my truck for airing up tires etc. I took two male quick disconnect fittings and screwed them together. This allows me to connect the glad hand on the truck to my shop air. Now I can air up the truck before I start it. This lets me get it out of the barn without filling the place with smoke and soot. I start it and drive it out. It will also come in handy locating that pesky air leak I have as soon as I get the time to dive in to that.

 

[G744]

Determine what type brake fluid is in it first: DOT-3 or DOT-5.

Don't mix 'em!

Dennis

 

[davidb56]

Go through everything, especially with a single circuit.
when mine takes a dump (dual circuit) I will do a HydroBOOST complete conversion that will allow me to add power steering at a later date.

 

[G744]

Where are you going to get vacuum?

D

 

[davidb56]

Where are you going to get vacuum?

D

It uses a power steering pump like on a older ford IDI, but larger......did I state the wrong name for it?

 

[davidb56]

yes I sure did, HYDROBOOST. hydraulic assisted brake booster.......Not vacuum assisted.

 

[The King Machine]

I would financially prepare to replace everything. I took no chances.

I started inspections at the wheel hubs and worked my way up. I ended up relacing all 6 wheel cylinders, all rubber lines, two steel lines, master cylinder, and rebuilt the air pak. Mainly due to pitting in the cylinders. Added the external reservoir, drained and flushed the system, refilled with DOT 3.

Other then a bleed here and there and the odd leaking wheel cylinder it has had no issues.

 

[DaneGer21]

Cleaning out the cab from the previous owner, I found a wheel cylinder and about 2quarts of DOT 3.

Knowing it takes DOT 5, I reached out to him, yet again. He’s probably thinking I’m a pain by now, but then again, he should be happy I care enough to get things fixed.

Anyways, he told me he previously flushed out the system and used DOT 3, he stated there was a bad wheel cylinder(hence he bought the new one), but he didn’t remember which side or which axle.

Knowing he used DOT 3, I can fill the system with what I already have and I can check for leaks that won’t cost me an arm and a leg to find haha


For now here are pictures, I really don’t see any old residue anywhere? Maybe one where the paint is flaking more than others?

Pics…
Driver Rear
Passenger Rear
Driver Intermediate
Passenger Intermediate
Driver Front
Passenger Front

 

[dmetalmiki]

I did something similar. I carry an air hose on my truck for airing up tires etc. I took two male quick disconnect fittings and screwed them together. This allows me to connect the glad hand on the truck to my shop air. Now I can air up the truck before I start it. This lets me get it out of the barn without filling the place with smoke and soot. I start it and drive it out. It will also come in handy locating that pesky air leak I have as soon as I get the time to dive in to that.

That 's what we do.....saves the lungs
(of other people!)

 

[dmetalmiki]

I had my GMC delivered fully rebuilt, but the brake seemed 'dodgy'
I replace the seals in all the wheel cylinders, 12 on a GMC M135.
Had the master cylinder A|ND brake booster overhauled
Use dot 3 .
cleaned and applied protection to all brake lines.
I feel safe now.
REMEMBER..on these trucks.. ONE OUT ALL OUT!
Somewhat gratified the Hand Brake is a (Whopping great) Propshaft DISC Assembly.

 

[Mullaney]

That 's what we do.....saves the lungs
(of other people!)

.
It is neat to see that sort of pre-planning. Our city has more of our money than they know what to do with. On the other hand, a few years ago I was really impressed when the Fire Department installed clamp on exhaust hoses with an evacuator fan to force truck exhaust out of the building. All the enginehouses have tile walls and they were cleaned as part of the upgrade.

The other part was adding an air compressor and plumbing to keep the trucks aired all the time. That hose setup was "breakaway" so something stupid couldn't fracture an air line in the truck system. In their study there was a possible reduction of as much as 30 seconds in response time - making it a really good investment.

Their mechanics have always been good at finding and solving air leaks. SOP is to crank the truck at least twice in 24 hours, so there shouldn't be time required to "build air" but just in case - that problem is solved.

 

[frank8003]

Ok, let me start by saying my truck has ZERO pedal for braking. Most of you reading this know I just got my truck running the other day. The brakes are the next thing on the list that need repaired.(I do know I have one bad air tank, I have a new one in route and that will be replaced first)

Anyways my question is, Would you start at the beginning of the brake system(master cylinder) or at the end(wheel cylinders, shoes, etc)?

Or should I just plan on going through EVERYTHING?

Any thoughts? Or experience as to where to start, or any certain things that are just common issues and where to look.

Thanks!

***For the record, I have NOT inspected or looked at ANYTHING brake related yet***

Start at the beginning
Is there fluid in the MC now?
Anyhow here is a few photos

You don't know what you got until inspection time.
Here start with a mess.

 

[DaneGer21]

It did have some fluid left but very close to empty. I topped it off. I then when to the bleeder at the air pack and bled until no air. That’s when I noticed a leak at the rear axle, a broken line right at the t-block. I removed the rubber line that goes to the rear axle, and I put a plug in it. So as of now I have “removed” the leaking rear axle lines from the system as if they didn’t exist so I could move forward bleeding and checking the lines.

I moved up to the intermediate axle and bled both sides accordingly with no issues. Then to the front axle and bled both sides, again with no issues.

I topped off the MC as needed when needed. The peddle got very stiff and I felt good about it. No leaks and a stiff pedal while the truck was off.

I then went to my air tank where I know I have a pin hole leak. FOR TESTING PURPOSES ONLY I ran a self tapping screw in the hole and through the tank. ***I already have a NEW tank headed here***

I fired up the truck, and let it idle for a few minutes. It idles at 850rpm now when warm. All of a sudden the Low Air buzzer went off at it was holding about 90psi.

We have 20acres and a loooong driveway so I headed for a trip down and back to the mailbox.

Here’s what I noticed. The pedal is VERY STIFF, but the truck stops. I felt like I had to put a heavy foot on it, but it did stop. I’m guessing the air pack will need gone through.

Thats it for now.

 

[98G]

See what it does after sitting overnight or a couple of days.

 

[frank8003]

Lube the airpak and find where the system is vented to now. It may or may not have been updated.

 

[DaneGer21]

I’ll check tomorrow.

As for now I remember the MC cap had what looked like an axle vent cap installed, it made for a fast removal of the cap, I was surprised. The original vent line was still sitting to the side unhooked and not capped.

 

[cattlerepairman]

I’ll check tomorrow.

As for now I remember the MC cap had what looked like an axle vent cap installed, it made for a fast removal of the cap, I was surprised. The original vent line was still sitting to the side unhooked and not capped.

Ah, that! Originally, the MC cap was vented via this line to the air filter housing. That caused issues and was to be disconnected and replaced with the axle vent. That also causes issues because it only allows flow in one direction, providing it doesn't stick, allowing no air flow.

The best solution is to do the remote reservoir mod;
Remove splash plate at underside of cap, thread nipple into cap, connect hose and run to plastic brake fluid reservoir with vented cap, located as per your liking on rear cab wall or engine compartment fire wall.

Easy check of brake fluid and keeps MC full.

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