2155 brake bleed problem

[GR Gold]

A little history on this tractor. I purchased from a local municipality that owned it since new. The nose of the tractor had been pushed back some and cracked the fuel tank. Some disassembly happened and then it was abandoned. I removed the nose, fuel tank, radiator, etc., and replaced several hydraulic hoses up there as well as the fan belt and hyd pump drive rubber cushion, and a good fuel tank. I also had to replace the left brake line that runs by the hydraulic filter as it was bent and ran under the filter and the line cracked when I was trying to bend it out of the way. Fast forward to now. I have replaced the hyd filter and several hoses, and refilled the Hyguard. The hydraulic reservoir and oil cooler were drained when I replaced the hoses. Following the owners manual on bleeding the brakes, it says to run the engine at 2100 rpm for 2 minutes “ Thus making sure the brake reservoir is filled with oil”. I have a clear tube on the bleed screw and the other end has about an 18” piece of copper tubing that is stuck down in the oil through the fill cap. I have cycled the 3 point several times and turned the steering back and forth from lock to lock, so I believe the hyd system is functioning ok. Problem is, I cannot get the brakes to bleed. When I open the bleed screw a bit and cycle the brake pedal up and down, I cannot get all the air out. I get spits of fluid through the hose, but mostly air. I have done this for at least an hour. It looks like the supply source for the brakes is the small line coming off the hyd reservoir and running back to the “y” and down to the brake pedal area. I am not sure what the “brake reservoir” is that the manual is referring to. Is there another thing I should attempt to bleed here? I sure am getting frustrated. Thanks in advance for all your replies!

 

[MSD]

Don't know if it has anything to do with the brakes not bleeding but did you clean the screen under the transmission case? They get pretty nasty sometimes.

 

[GR Gold]

Don't know if it has anything to do with the brakes not bleeding but did you clean the screen under the transmission case? They get pretty nasty sometimes.

Yeah, and it was pretty nasty. Did it when I changed the fluid and filter.

 

[Fixingfarmer]

Do they function?

Sometimes they don’t bleed like you would expect on a car they use hydraulic pressure and will self bleed better as you use them.

 

[Jim.ME]

Yeah, and it was pretty nasty. Did it when I changed the fluid and filter.

Did it have flaky friction like material on the screen?

 

[GR Gold]

Did it have flaky friction like material on the screen?

No, just black gunk.

 

[GR Gold]

Do they function?

Sometimes they don’t bleed like you would expect on a car they use hydraulic pressure and will self bleed better as you use them.

I actually drove the tractor on and off the trailer and to where it is parked now under the shed. They worked good BEFORE I messed with it. Now, both pedals go down to the floor with no resistance. I haven’t tried bleeding the right one, only the left one. Maybe I should try the left one.

 

[Fixingfarmer]

I strongly recommend you purchase manual TM4436 it’s the testing and operation manual for 2155-2755 tractors

They are available at John Deere publications

Possibly elsewhere

There’s another service manual but it’s how to repair if you were doing a head gasket or know what the problem is on anything both are 200 plus bucks if you are going to purchase one that is the one for electrical schematics as well

Here’s a diagram of your brake supply

It will be fed from the steering up top

There’s no reservoir specifically for brakes that I’m aware of there is a reservoir above main hydraulic pump E that is a surge

This is fed by transmission oil pump

The diagram shows that supply line from steering should come down to the inside fitting of the brake valve you could take this off and start the tractor see if you have flow. CAREFULLY into a pail.

The picture I took of the tee shows the fitting that should feed both steering and brakes

 

[Fixingfarmer]

You should also be able to bleed one side then the other I might be tempted to take the hose off down below and see what’s actually coming out into a pail as well

 

[Harry in Ky]

What I'm getting from the post so far, this tractor doesn't have an orbitrol type steering valve, so the diagram posted above won't apply. The fluid in the brake valve is supplied internally by fluid from the steering system.

 

[Jim.ME]

There’s no reservoir specifically for brakes that I’m aware of there is a reservoir above main hydraulic pump E that is a surge

The cavity in the brake valve body is the brake reservoir. I don't have a 2155 manual, but I know that is called out as the reservoir on some other JD models using that or a similar brake valve. There should be a plug in the top that can be removed to check for fluid in it.

 

[GR Gold]

I strongly recommend you purchase manual TM4436 it’s the testing and operation manual for 2155-2755 tractors

They are available at John Deere publications

Possibly elsewhere

There’s another service manual but it’s how to repair if you were doing a head gasket or know what the problem is on anything both are 200 plus bucks if you are going to purchase one that is the one for electrical schematics as well

Here’s a diagram of your brake supply

It will be fed from the steering up top

There’s no reservoir specifically for brakes that I’m aware of there is a reservoir above main hydraulic pump E that is a surge

This is fed by transmission oil pump

The diagram shows that supply line from steering should come down to the inside fitting of the brake valve you could take this off and start the tractor see if you have flow. CAREFULLY into a pail.

The picture I took of the tee shows the fitting that should feed both steering and brakes
View attachment 164052View attachment 164053View attachment 164054

The pictures and diagram you sent are a little different than what I have.

I strongly recommend you purchase manual TM4436 it’s the testing and operation manual for 2155-2755 tractors

They are available at John Deere publications

Possibly elsewhere

There’s another service manual but it’s how to repair if you were doing a head gasket or know what the problem is on anything both are 200 plus bucks if you are going to purchase one that is the one for electrical schematics as well

Here’s a diagram of your brake supply

It will be fed from the steering up top

There’s no reservoir specifically for brakes that I’m aware of there is a reservoir above main hydraulic pump E that is a surge

This is fed by transmission oil pump

The diagram shows that supply line from steering should come down to the inside fitting of the brake valve you could take this off and start the tractor see if you have flow. CAREFULLY into a pail.

The picture I took of the tee shows the fitting that should feed both steering and brakes
View attachment 164052View attachment 164053