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General Forestry => Forestry and Logging => Topic started by: mf40diesel on January 27, 2019, 08:50:54 AM

Title: Old TJ brakes / Disc conversion
Post by: mf40diesel on January 27, 2019, 08:50:54 AM
I run an old TJ 225, selective cut work, view lots, firewood etc...  machine is pretty darn straight. But like many it seems, she's has practically no brakes. (The band brake works, but foot brake doesn't, or very little.)

Currently I am working on a pretty steep side hill, trying to regain a view for some people. Had a few little scares...  brakes have moved up on the "to do," list. 

I believe I can rebuild the current drum brakes fairly easily..  however I know others have converted to a disk brake. Does anyone have any info on how that was done?  What parts/brackets to get?

Seems I heard it was pretty easy, but don't want to go into NAPA completely uneducated. 
Title: Re: Old TJ brakes / Disc conversion
Post by: 47sawdust on January 27, 2019, 08:58:18 AM
Seems the quickest is a rebuild.Harold's should be able to fix you up or point you in the right direction.
Also a forum search will show you how others have done the conversion on Tjacks.It was a topic recently.Good luck.
Title: Re: Old TJ brakes / Disc conversion
Post by: Firewoodjoe on January 27, 2019, 09:48:34 AM
I'd just google caliper and rotor kits and modifie it to your drive line.
Title: Re: Old TJ brakes / Disc conversion
Post by: Firewoodjoe on January 27, 2019, 09:55:58 AM
You'd also need a master cylinder which is not a big deal either. But I bet you'd have $300+/- into it and a fair amount of labor to build modifie. But after it was done man it would be cheap and easy to put new pads on.
Title: Re: Old TJ brakes / Disc conversion
Post by: mike_belben on January 27, 2019, 12:44:52 PM
Personally i dont think loss of brakes when the engine stalls should be acceptable, which is what my forkloader has and it is only by the grace of god the thing has killed anyone.

You want to build a system that does not need a fluid or vacuum assist.  So thats old manual master cylinder disc brake systems.  You want a SMALL master cylinder piston, not a large one.  The large one has too much area and requires too much input force.  

I recommend a 79 thunderbird master cylinder, cadillac eldorado calipers with a manual ebrake lever and whatever rotors u need to adapt onto your driveline.  Its not hard to transfer a hub pattern onto a plate, cut out, weld it onto the shaft, bolt up the plate and caliper to lathe turn them back true while bolted to the driveshaft.  Or you could probably incorporate the rotor mount to some pinion yokes, though welding onto cast takes some procedure.  If replacement yokes were unobtanium i wouldnt risk it.

AA-mfg makes all the cheap GM caliper brackets u can imagine to mount them.  


With approx 3:1 planetary axle ends, even a motorcycle hydraulic hand brake may suffice.  Long periods of braking require mass to dissipate heat, but parking just takes force. Depends on your needs. 
Title: Re: Old TJ brakes / Disc conversion
Post by: 47sawdust on January 27, 2019, 03:21:48 PM

Forestry and Logging (http://forestryforum.com/board/index.php?board=4.0) / Re: timberjack brake (http://forestryforum.com/board/index.php?topic=59369.msg1611701#msg1611701)
« by skolvek (http://forestryforum.com/board/index.php?action=profile;u=42508) on November 06, 2018, 06:12:50 PM »
This thread has more info.which might lead to more info.
Title: Re: Old TJ brakes / Disc conversion
Post by: mf40diesel on January 27, 2019, 08:13:37 PM
Thanks so much for the info. Prolly should have called Randy first...  surely he'll have everything

When working of flat ground, it hasn't really bothered much...  but a couple times recently, I stomped hard on the binders and barely got anything. 

I'm not telling the wife anything about that!
Title: Re: Old TJ brakes / Disc conversion
Post by: Stoneyacrefarm on January 28, 2019, 10:23:04 AM
You've got Davco up your way as well. 
Their great to talk to on the phone as well. 
Give them a call. 
They may be able to walk you thru setting everything up. 
Title: Re: Old TJ brakes / Disc conversion
Post by: mf40diesel on January 28, 2019, 06:52:23 PM
Funny enough, planning on a trip to Farmington to run to Labonville for some supplies anyways. Was looking for a reason to go to Davco. That place is awesome. Although, more into the treefarmers then TJ's. Which aren't nearly as good. ;)   Lol 
Title: Re: Old TJ brakes / Disc conversion
Post by: tjtom on July 14, 2025, 09:24:49 PM
Quote from: mike_belben on January 27, 2019, 12:44:52 PMYou want to build a system that does not need a fluid or vacuum assist.  So thats old manual master cylinder disc brake systems.  You want a SMALL master cylinder piston, not a large one.  The large one has too much area and requires too much input force. 

I recommend a 79 thunderbird master cylinder, cadillac eldorado calipers with a manual ebrake lever and whatever rotors u need to adapt onto your driveline.  Its not hard to transfer a hub pattern onto a plate, cut out, weld it onto the shaft, bolt up the plate and caliper to lathe turn them back true while bolted to the driveshaft.  Or you could probably incorporate the rotor mount to some pinion yokes, though welding onto cast takes some procedure.  If replacement yokes were unobtanium i wouldnt risk it.

AA-mfg makes all the cheap GM caliper brackets u can imagine to mount them. 

You are a legend. Thank you! I want to do this to my TJ208 i know this is an old thread but its still gold. Do you have any more details in terms of a particular disc or caliper?. After googling thunderbord cylinder i found this description:

Fits 1976-1979 full size Ford
Single bail cast iron
Dual well master cylinder
Features a 1" bore and 9/16" and 1/2" ports on right side
Application Disc / Drum

Universal fit made for disc brake conversions with a dual bail fluid compartment and adapter for power or manual brakes. Can be used for manual or power applications. Deep bore with a shallow bore adapter included.  Fits all MBM's brake boosters with 3-3/8 center to center stud spacing.