Understanding Wet Brakes

Texasmark1

Well-known Member
Recently purchased 1988 3910 and seems to have the same braking system as most Fords of the size/era. Discs are C5NN2A097B.

Tractor only has 900 hrs for being 30 years old. Very little, light weight usage as were the actual hours posted, verified by me several ways.

Assuming the wet brakes were sitting half in and half out of oil, even though the tranny shows the very slightest bit of rust in a non contact area, in an area on a shaft above the oil.....(separate sump but metal exposed to the atmosphere somewhat to the same degree) I have a low pitched grinding noise when applying the brakes, with any degree of pressure, both sides, at any speed..

The braking performance is excellent and it's grinding (not chatter). The adjustments are about midway and even. No sign in the adjustment nor the pedal height when applied, that anything is worn down, aka worn out. The noise was present when I bought it and after I changed fluid and hyd spin on filter. Oil was dirty like was in the tranny but no signs of moisture in either.

I don't know how the thick the friction material is on the brake disc and just what it's made of......would really like the answer to that question without having to buy a disc just to see. I'd assume It would be like a clutch disc lining, very hardy and resistant to usage......seems to me it has to be that way when you consider what it takes to get the axles off to get at the brake assemblies and all.

I have put about 20 hrs on the tractor since purchasing and they were medium duty requirements, 6' drum mower and 7' tandem disc harrow. Noise hasn't changed. I was hoping I had rust on the steel plates that rub against the discs when stopping and that I could gently rub it off with some usage. Apparently not.

I tried to answer all your questions prior to your asking. Assistance would be appreciated.
Thanks,
Mark
 
I?d change the hydraulic oil and filter(s) before I gave a thought to replacing the brake discs. Wrong or contaminated oil does make brake noise and or chatter. Find a New Holland dealer that stocks 134 oil, stay away from MasterTran Ultraction for now. There have been instances of brake noise in Fords that have had 134 and switched to MTU.
 
Those brakes are about bulletproof, so unless a prior owner intentionally abused them, they're not wore out.

The friction material is not very thick - it doesn't need to be because they don't really wear. The material looks and is very similar to the friction linings that you'd find in an automatic transmission.

I doubt the noise you hear is metal to metal grinding. The most common noise coming from those brakes is a squawk, which is more related to the kind of oil you have than anything else. I'd do what Rick suggested, or else try and find some of the anti-chatter additive that they made at one time for those brakes. Not sure if you can get that now or not anymore.

If you're really concerned about it, they're not that hard to get at to inspect, assuming you don't have a loader or rusted up roll bar on it.
 
This is a NOS brake disc from a 4000.
It's gotten rained on a few times but has never been run. You can see what I think is brass or bronze wear portion which has been bonded to the steel disc.
You can kinda see the brass wear surface is only about .025? thick when new. The brass wear area is on both sides of the disc. There are two of these discs on each side.
a279040.jpg
 
Cheap oil. Change to 134D or oil that specs to it. Them brakes will last 10,000 hrs or more. Change filter while at it.
 
So, we are dealing with metal on metal with one metal being a sacrificial element, not epoxy or some organic substance with pieces if metal embedded.

That makes sense given as I said, the difficulty (and obvious expense) in replacement and to consider that they were replacement for regular drum brakes that lasted for 10's of years.

Thanks for the show and tell sir.
 
Given the overall condition of the tractor and the fact that it was a one owner, maybe in his 80's when passing on this year, his estate appeared to be in tidy order, I doubt it was abused. It had been shedded which supports the type of service it received.

I just want to ensure to myself that I'm not hurting anything. This thing is so much more than my 3000 it's just what I wanted to fill in a gap in my corral. It's a big tractor in a little package and works beautifly with both implements Ihad planned for it.

Thank you sir for your time.
 
They are indeed 10,000+ hour brakes. My 4600 rolled past 10,000 hours last year, and still has the original brakes. They groan some, too. I don't like it, but they keep working. I wouldn't worry about yours.
 
(quoted from post at 16:48:03 09/06/18) Recently purchased 1988 3910 ... I have a low pitched grinding noise when applying the brakes, with any degree of pressure, both sides, at any speed..

The braking performance is excellent and it's grinding (not chatter).

Just an add on to what was stated previously. I believe your brake friction material is called sintered bronze. Doesn't sound like it's worn out from your description of your pedal height. Ford used to sell an anti chatter additive (friction modifier). Call NH and ask it it's still available. Alternatively, Caterpillar will have the additive if NH does not. When CAT built the 416 series, they licensed the differential, brakes and axle housings from FNH. CAT is big on the little details like friction modifier. They may tell you it's in their TDTO Transmission/Drivetrain oil and that's what you need to use. Ask for the friction modifier first and add it to your oil as that's the cheapest way to find out if the problem is in your brakes or not.
 
You said you changed the oil without specifying what was used. I?ll stick with my recommendation to put 134 oil in it. J20 is, as you know, a Deere spec and IIRC an old spec at that. Deere uses a completely different brake material.
 
(quoted from post at 03:22:18 09/07/18) ... I'll stick with my recommendation to put 134 oil in it. ... J20 is a Deere spec ... and Deere uses a completely different brake material.

Ford sold the anti-chatter additive to go with their 134 oil when needed. Like Rick says, stick with the 134, now made by CNH's subsidiary Ambra. Messicks shows an Ambra Axle Oil Additive is still available. I can't tell from the photo whether it's for anti chatter. You'll have to call them to find out. Here's a link.

https://www.messicks.com/part/87304782/16-fl-oz-axle-oil-additive Messicks Parts Dept. 877-260-3528

I don't know if Messicks will ship oil UPS. If all else fails and NH is 200 miles away, call your local Caterpillar dealer. If they're not local, they should have a drop box within 25 miles of your location that's populated every night with whatever you order.
 

I've had two tractors with worn wet brakes, 1st was my 4500 that would still stop but was out of adjustment. Don't know how many hours on the tractor but it had worn out it's 2nd engine when I got it.
2nd was a 94 model 3930, the right brake had good pedal but had no braking power, I found the return spring under the right foot board was missing, this allowed the brake to drag constantly prematurely wearing it out.
Without the return spring the weight of the pedal is enough to cause the brakes to drag constantly.

My other 4 wet brake tractors still have their original brakes with plenty of pedal adjustment and good braking power, 66, 69, 72 and 89 models.

The brakes on my 6610 groan every time I stop which is a lot when baling 900-1000 rolls of hay per year for the past 9 years.
I was a bit concerned at first but pay little attention to it now, tractor stops good and the brakes have never been adjusted.
 
Well folks, thanks for your time. I do appreciate the responses.

I subscribe to the addage "If it ain't broke don't fix it". Apparently "they ain't broke" so no needing a fixin. Besides I really don't want to tackle a job like that alone (how I work) when it's iffy that all the time and worry might just be a waste of time.

Mark
 
Blenders can print pretty much whatever rating they want on a pail. Results matter. I can?t tell you how many customers have eliminated wet brake concerns by filling the rear axle with OEM oil. I wish you luck.
 

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