Brake Grinding sound

[TommyJD790]

I have had my 2001 John Deere 790 for about 2 months now, and everytime I head down a steep slope and need to apply the brakes, it makes a grinding or maybe ratcheting type sound. It sounds like it's coming from the rearend.
I can't tell if it's only on one side or both.

Is this normal ?

Tommy..

 

[beenthere]

Are you applying both left and right brake pedals at the same time?

Is the sound the same if one or the other brake pedal is applied?

 

[RoyJackson]

My 790 only has a couple hundred hours on it...I do hear that "grunching" sound one hears with glazed disk brake pads on occasion, so your brakes may be fine. But it'll pay you to check them out or have the dealer do the work.
With 9 years on the tractor, it may be time for new brake shoes. The 790 has dry brakes on the rear axle only. The shoes may have a glaze on them (which can sound like grinding), but at that tractor's age (especially if it has 500 hours or so), it's probably best to pull the axles (790's brakes are inboard, by the differential) and take a look.
Before you do this, contact your dealer's service department and find out if there's an inspection port so you can see the brake shoe thickness before doing any disassembly. If you have a manual (I do, but it's on another computer), check that out first to see if there is an inspection port.
Since you don't know how the previous owner operated the tractor (he may have been riding the brakes continously), it's better to check them out soon.

 

[beagleboy]

I'm not sure if you have wet type brakes or dry type brakes, but my 1070 has wet type and the brakes would chatter when you used them when turning and I got some antichatter fluid from John Deere and it took care of the problem,but again maybe the 70 series did go to dry type.

 

[Muxster]

Here is the section from the manual on brakes. They look pretty easy to work on.

 

[TommyJD790]

Are you applying both left and right brake pedals at the same time?

Is the sound the same if one or the other brake pedal is applied?

Yes.. I was applying both brakes at once. I just went out and tested the brakes and it is definitely only the left side. After doing a couple donuts with only the left brake locked up, it seemed to make less noise. I know this tractor was sitting on a dealers lot for a while, and I've only put 4 hours on it since I got it, so could it maybe be some rust on the shoes or hub or something like that ?

TommyJD790 ...

 

[TommyJD790]

Here is the section from the manual on brakes. They look pretty easy to work on.

Thanks for looking this up Muxster. I think I need to purchase this manual. What manual is this from ?

TommyJD790..

 

[Barely Smokin']

Tommy,

The brakes on my 790 were squealing like there was a dying cat inside each hub. Thought for sure it was the pads, bought new ones---NOT CHEAP---like $60+ each, and you'll need four.

Took everything apart (easy) and the pads were fine. Only glazed. So, I just used them regularly and the squeal eventually went away.

 

[Muxster]

Thanks for looking this up Muxster. I think I need to purchase this manual. What manual is this from ?

TommyJD790..

Your welcome... I bought the service manual (TM2088) on CD from JDparts.com

 

[RoyJackson]

Thanks for looking this up Muxster. I think I need to purchase this manual. What manual is this from ?

TommyJD790..

Your Dealer can get you the manual. It's about fifty bucks if you buy it on CD-ROM.
There have been at least three revisions to the 790, so make sure you buy the correct manual. You'll want the first one for a 2001 790 (probably be combined with the 670, 770, 870, 970 and 1070 tractors as they shared many components and designs).
The correct manual is most important for the electrical schematics.
Muxster's attachment is from the factory manual. The aftermarket manuals leave much to be desired.

Barely Smokin's idea of easy much be him having help with those 400 pound tires.