TN75 brake master cylinder replacement

[Rollin14]

early 2000s TN75 4x4 open station...had one of the brake master cylinders replaced a few years ago at a cost of about $1k...other cylinder is now going out.

two questions...
OEM cylinder is either $500 or unavailable and there are quite a few aftermarket ones out there for $100-150 - anybody have any experiences good/bad with aftermarket master cylinders?

on the replacement - anything odd that needs to be done when replacing one? I have the mineral oil and guessing the lines would need to be bled off somehow

appreciate it

 

[Roadworthy]

I've got no experience with aftermarket master cylinders but if you can find a kit some can be rebuilt.

 

[farminfool]

early 2000s TN75 4x4 open station...had one of the brake master cylinders replaced a few years ago at a cost of about $1k...other cylinder is now going out.

two questions...
OEM cylinder is either $500 or unavailable and there are quite a few aftermarket ones out there for $100-150 - anybody have any experiences good/bad with aftermarket master cylinders?

on the replacement - anything odd that needs to be done when replacing one? I have the mineral oil and guessing the lines would need to be bled off somehow

appreciate it

I'm just wondering what your symptoms were. I have a tn65 and it seems like the rear brakes are dragging bad parking brake seems to be releasing.

 

[LouNY]

I'm surprised that your master cylinders are so high, they look like mine for the 8160.
I ended up with aftermarket through my NH dealer, could have saved $50+ going aftermarket myself.

 

[TractorTech]

I would be comfortable with the aftermarket.

As far as installation goes, they are not difficult to install and yes, bleed like any brake. Bleeder on the axle can sometimes be difficult to get to, but that’s about it.

 

[Rollin14]

I'm just wondering what your symptoms were. I have a tn65 and it seems like the rear brakes are dragging bad parking brake seems to be releasing.

Symptoms were like you mentioned...just felt like it wasn't pulling like it should. Usually I could pump the brakes and it'd stop dragging.

One easy way to check the cylinders would be to uncouple the pedals and see what amount of tension they have on them.

I had the other cylinder replaced several years ago...the first time I knew I had a problem I was dragging a horse arena and the tractor almost came to a complete stop on me....clutch/transmission going out were my first thoughts...I literally shut it off, messed around with it for about 15 mins and no problems again that day....didn't think about brake issues until a few days later I was using it right at dusk and all of a sudden my brake lights came on...noticed the glow on the fender.

Looking back that should've been the red flag for the brake pedal/cylinder, but I was focused on the parking brake because mine, although it works fine, takes a little moving it around to get it to completely release or it releases but the light is still on. For a couple weeks until I got it fixed, during the day I'd literally hold my hand back by the rear marker lights and when I felt it dragging I'd look back and sure enough, brake light was on. May be wrong but I think only the outside pedal triggers the brake lights.

After several weeks of trying to diagnose it, I finally just took it to a local shop and almost a grand later I had one cylinder replaced.

The first time I felt it this time around I uncoupled the pedals and sure enough the other cylinder didn't have any tension on it.

I replaced it with this aftermarket one...

https://www.fridayparts.com/brake-master-cylinder-87354675-for-new-holland-tractor-tn75va-tn60a-tn70a-tn75a-tn60va-tn70va-tn85a-tn70na-tn95a

There was a review that mentioned that the pushrod on the replacement cylinder wasn't the correct length and sure enough, I had to swap the one from the failed part to the new one...excuse to buy a new snap ring tool

I probably took apart more than I really needed to as they are a little hard to access (and I don't exactly have a shop with tools or the area to work on it) but all in all I was able to get it changed out for less than $200 including the replacement part, mineral oil and a couple random tools. I took apart most of the dash as I ended up removing the lower panel on that side to be able to get to the inner cylinder. think the FEL bracket was also in the way as well

knock on wood - but 5 months in and working good

 

[LouNY]

That is some expensive brake oil also about $20 quart. But with the price of master cylinders it's not bad I ended up giving $173 each at my local NH dealer for aftermarket units and one of them was bad as received.
Mine went out because the previous owner used DOT 3 fluid in them. Still have my fingers crossed as too the health of the actuating pistons but they are feeling decent so far.

 

[Tractor2Big4Me]

Reviving an old thread, but hopefully it will be helpful to someone. I bought a used low-hour TN65 this past summer and the inner master cylinder started leaking the first time I used the tractor heavily. The seal failed where the pushrod entered, probably because the tractor hasn't been used much. After looking at the New Holland part prices ($500 each), I bought two of the FridayParts master cylinders for about $105 each--I thought it was probably worth the risk for the cost savings. They came quickly and seemed to be of good quality. I thought I might as well replace both of them since accessing the inner one pretty much requires removing the outer one. I was able to get both of them off without removing the plastic dash liner using a hex socket with a ball end and a long ratchet extension. I did have to swap the push rods because the FridayParts ones were shorter than the originals. A cheap set of C-clip pliers did the swap job quickly. I strongly suggest buying new copper crush washers because I didn't do it and I have a slight seep that will require another disassembly and bleeding again someday. Make sure you get the correct brake fluid--do NOT use DOT 3 fluid. The correct fluid is based upon mineral oil and I could only find it at the dealership or online (about $20-25 per quart). Get a quart, because it isn't much more expensive than a pint. When you get everything hooked up, make sure you fill the reservoir to the very top, or you may not get fluid to cross the internal divider wall and you will not be able to bleed one side properly. This drove me crazy and I thought I had a bad master cylinder until I realized what was happening. Bleeding the right ("passenger") side brake is a pain because the Lift-O-Matic mechanism is in the way of almost every wrench I owned. I ended up buying a vacuum hand pump bleeder that made the initial bleeding easier. Then, my wife pumped the brakes while I cracked the bleeders to finish the job.

Other than the mishap with the reservoir causing one side to starve for brake fluid, the job isn't that horrible. You will need the aforementioned ball-head hex set, a 17mm wrench for the banjo bolts, and bandaids for when the sharp plastic edges of the lower dash panel succeed in bleeding your hands. I think the bleeder screws are about 14mm if I recall correctly. I ended up using most of the quart of brake fluid by the time I disassembled the system several times double-checking everything. Just wish I had put new copper washers on when I did the job...