John Deere 7710 brake responsiveness

[TNSmassey]

Evening all.

Looking into a JD 7710 that is slow to respond when you press the brake pedal.
We have put a gauge on the trailer brake coupler and that appears to ramp up the pressure as soon has you press the pedal so no problems there.
Shunting around the yard you would hardly notice anything wrong but if you go off down the road at 40K and hit the brakes, there a delay before the brakes are applied. Were probably only talking of 1.5 seconds but when Dorothy in her Fiat Panda pulls out in front of you, she's likely to have a weight block imbedded in her bonnet.

The tractor has had new brake discs, pistons and obviously seals already but did not improve the responsiveness.

Any thoughts on this would be much appreciated, I didn't think it was that bad until I tried it for myself so there is a genuine problem.

Does a 7710 have a brake attenuator like a 6910?
I noticed that the 4wd light doesn't come on when you brake, is that normal on a Deere?

TIA

T

 

[Robt]

Rear brake light bulbs?

 

[Deerefarmer]

All 7010s I've ran that had a hydraulic trailer brake had a slight delay, under the floor at your feet there is a delay valve in each brake line .

When installing the field installation kit on ones that weren't equipped with factory trailer brakes I stopped putting the delay valves in for that reason. Doesn't seem to hinder performance so can't see any harm in removing them if you want to see if that makes a difference

 

[Flat 10]

Evening all.

Looking into a JD 7710 that is slow to respond when you press the brake pedal.
We have put a gauge on the trailer brake coupler and that appears to ramp up the pressure as soon has you press the pedal so no problems there.
Shunting around the yard you would hardly notice anything wrong but if you go off down the road at 40K and hit the brakes, there a delay before the brakes are applied. Were probably only talking of 1.5 seconds but when Dorothy in her Fiat Panda pulls out in front of you, she's likely to have a weight block imbedded in her bonnet.

The tractor has had new brake discs, pistons and obviously seals already but did not improve the responsiveness.

Any thoughts on this would be much appreciated, I didn't think it was that bad until I tried it for myself so there is a genuine problem.

Does a 7710 have a brake attenuator like a 6910?
I noticed that the 4wd light doesn't come on when you brake, is that normal on a Deere?

TIA

T

Is the 4wd light working?

 

[TNSmassey]

All 7010s I've ran that had a hydraulic trailer brake had a slight delay, under the floor at your feet there is a delay valve in each brake line .

When installing the field installation kit on ones that weren't equipped with factory trailer brakes I stopped putting the delay valves in for that reason. Doesn't seem to hinder performance so can't see any harm in removing them if you want to see if that makes a difference

This sounds possibly!! Thanks for that!
What do they look like? Assuming their online with the brake lines?

 

[Deerefarmer]

This sounds possibly!! Thanks for that!
What do they look like? Assuming their online with the brake lines?

Yeah. In the brake lines.

Remove floor mat and metal plate
The delay valves will have a triangular stamp marking in them pointing In direction of oil flow

 

[Phil P]

This sounds possibly!! Thanks for that!
What do they look like? Assuming their online with the brake lines?

They’re just like a fitting that joins the metal pipes to the rubber hoses under the floor plate. They’re there to slow the flow of oil coming back from the brake pistons so if you have to reapply the brakes in quick succession they respond quicker.
However they can get worn and stick on the valve seat and either not open instantly causing a delay or cause the brakes to stick on for a few seconds to long. As @Deerefarmer says removing them would be a good place to start. I’d also check the standby press on the hydraulics is set correctly as that will cause a delay in the pump reaction time if it’s down.

 

[TNSmassey]

Yeah. In the brake lines.

Remove floor mat and metal plate
The delay valves will have a triangular stamp marking in them pointing In direction of oil flow

 

[TNSmassey]

Floors up and I have found one connector with a triangular stamp on it.

mid this what you meant

thanks

T

 

[AnyOldName]

I think the same check valves are shown in this video (17mins 40sec) if you don’t want to watch it all.

 

[TNSmassey]

Thank you very much!!
Taken the valves out today and the customer was really pleased with the result.

Thanks again

T