Advice Needed: How Do I Bleed These Brakes?

Hello everyone

Just to preface my post, I think I have a simple problem, but I have very little knowledge on how to maintain a tractor.

Anyway, I have a small tractor that my Grandfather made out of odds and ends 40~50 years ago. Here's a photo of it:



It runs great, but I've lost the brakes. Years ago when the tractor was left in the care of my Dad and myself, the brakes gave out.

The issue was it ran out of fluid. They must have been slowly leaking undetected for years. Either way we refilled the reservoir, supposedly bled the brake lines (I don't remember exactly what we did), and we thought we fixed the issue. That was until the next morning when we found the fluid had leaked onto the floor.

At that point we assumed the issue was bigger than what we could handle and left it. The tractor has an emergency brake that works well enough.

But lately, the notion that we didn't properly bleed the lines has been stuck in my mind. Let me show you some pictures; perhaps someone may be kind enough to walk me through what needs to be done.

Image 01:



Here's the pedal and reservoir. There is no pressure when depressing the pedal, and there's probably 3/4" of fluid left in the reservoir.

Image 02:



Underneath the pedal is the line heading towards the back wheels. One thing to note, the rubber where the pedal pushes into the area under the reservoir is in pretty rough shape. Is this bad? In case I need to replace it, what is this thing even called?

Image 03:



Continuing down the line, here is where the line splits in two. I've got a feeling we may have loosened this back when we thought we were properly bleeding the brakes.

Image 04:



This is the last I can see of the line. In order to get access to the parts beyond what we can see here, I'd have to remove the fenders. But this is what has got me thinking. I've got a feeling the part I need to get access to properly bleed the brakes is beyond this point.

What are your thoughts? I've never done something like this, so I'd appreciate all the advice I can get.

Thank you very much.

Yes, you need to pretty much get to the end of the lines, which is the wheel cylinders, to get it bled.

The fluid leaked unto the floor because you have a leaky master cylinder, slave cylinder, brake lines or a combination of those.

It did NOT leak because you improperly bled the system.

Put a little fluid in the system and let it sit a day or two and watch for leaks, then correct as needed.

If you have questions once you find the leak(s) post back and we will walk you through repairing them.

From the looks of the pictures I am going to say that the leak is at the slave cylinder / rear wheel. The picture shows a wet drum.

Agreed to putting fluid in the reservoir and wait to see where it leaks out. Even pumping the pedal will help work the fluid out of the leak.

Wow, thanks everyone for the quick replies! I've added some more brake fluid to the reservoir and will keep an eye out for leaks.

You have an "age related" leak, maybe more than one leak...

There are bleeder fittings on the top, back side of the brake back plates. Since that is the high point of the system, that is where the air is trapped. You might could access them by removing the wheels.

And while the wheels are off, pull the drums and look for fluid leaking out the dust covers on the wheel cylinders. If you repair the leaks now, you might save the shoes. Once they are fluid soaked, they are pretty much ruined.

The master cylinder could also be leaking. Check the boot, it should be clean and dry. If it's wet , the master cylinder will need to be repaired or replaced. That appears to be a early 60's era cylinder from possibly a GM product.

There are casting numbers on the cylinders to reference kits or replacements.

Here's a tip... If you do end up going through the entire brake system, (which is really the only way to fix it right), and you have a completely empty, flushed and cleaned system, go back with DOT 5 silicone base brake fluid. It is made specifically not to absorb moisture like glycol based fluid does. That moisture is what deteriorates the seals, even when just sitting like many show vehicles do. But, the DOT 5 is not compatible with any other fluid! The system must be completely empty and clean.

About 24 hours has passed since topping up the reservoir. Still no leaks; I'll continue to keep a close eye on things.

As Wi11y kindly suggested, I've tried pumping the pedal a few times to help work the fluid out of the leak. However, there is zero pushback from the pedal. If I depress the pedal, it stays depressed. Is this a typical symptom of a leaky, un-bled system, or could this be a sign that I have another issue?

Thanks again everyone, I really appreciate all the suggestions and tips!