ok. i have no rear brakes, so it is time. The question is, should i do the proven monte caliper swap or should i use all toyota and use the non vented mini truck rotors in back? These would be accompanied by minitruck calipers. i havent looked too hard at the spacing issues yet. should i just use the vented rotors? i have so many questions and yes i have read the tech sectiion. who knows? any suggestions?
rear disks (1 Viewer)
- Thread starter cavsfj40
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Rear disks are a great upgrade. I do however, have a '72 with 33's on it still running a fully functioning drum system that will put you through the windshield if you are not careful. 
I have been very happy using the GM system on my Land Cruiser for many(13) years. Have done swaps for, and know others who love having the GM set up on thier trucks.
Good luck!
-Steve
I have been very happy using the GM system on my Land Cruiser for many(13) years. Have done swaps for, and know others who love having the GM set up on thier trucks.
Good luck!
-Steve
I love my GM swap. It was easy and for the most part inexpensive. If I remember I was under 140 for everything. I pulled the monte calibers from a pick and pull yard, luckily it had what appeared to be new pads on it. I got the $26 rotors from Checker and had them milled out for $10 a peice. That was the extend of the cost.
I have read were some guys have gotten custome lines made to adapt fromt he toyota t box on the diff to the GM caliper. I opted not to do this. I cut the hard line off the car and the metal tab that the hard line and flex line mount to. So from the yard I got the caliper, pads, flex line, about 5 inches of hard line and the tab.
I cut my LC line just inboard of the spring mount (test fit your monte caliper) and slid the SAE nut on the line. I then double flared the line again with the SAE nut on it instead of the yota nut. I then mounted the brackets and calipers up and welded the tab to the axle and put the lines in and tightened them up. Looks clean and like it has been forever.
BTW, I paid like $86 for my brackets. I have seen them on ebay many times since with Buy it Now for $69.
I have read were some guys have gotten custome lines made to adapt fromt he toyota t box on the diff to the GM caliper. I opted not to do this. I cut the hard line off the car and the metal tab that the hard line and flex line mount to. So from the yard I got the caliper, pads, flex line, about 5 inches of hard line and the tab.
I cut my LC line just inboard of the spring mount (test fit your monte caliper) and slid the SAE nut on the line. I then double flared the line again with the SAE nut on it instead of the yota nut. I then mounted the brackets and calipers up and welded the tab to the axle and put the lines in and tightened them up. Looks clean and like it has been forever.
BTW, I paid like $86 for my brackets. I have seen them on ebay many times since with Buy it Now for $69.
I second phlyfish, the GM rear disk is a easy conversion.
I ended up buying a flaring tool and then making a metal mount for where the mating for the flex line to the hard line. Just eyeballed and cut the hardlines. Pic below is a mock fit, before i got everything snugg and painted. Just welded the mount tab i made on the the axle...worked out nice and looks clean...also keeps the softlines safe.
I know some use a proportioning valve to compensate. I got a mastercylinder off a FJ80. I'm not running yet, but I ran a post couple months ago and someone here had the same setup and said the matercylinder worked out great.
Good luck with it!
I ended up buying a flaring tool and then making a metal mount for where the mating for the flex line to the hard line. Just eyeballed and cut the hardlines. Pic below is a mock fit, before i got everything snugg and painted. Just welded the mount tab i made on the the axle...worked out nice and looks clean...also keeps the softlines safe.
I know some use a proportioning valve to compensate. I got a mastercylinder off a FJ80. I'm not running yet, but I ran a post couple months ago and someone here had the same setup and said the matercylinder worked out great.
Good luck with it!
toyota minitruck and Cruisers use a fixed-position caliper. The bolt solidly to the cast knuckle and have pistons on both sides to clamp on the rotor. The rotor MUST remain in a fixed location so they can clamp both sides with equal pressure.
Monte Carlos are a sliding pin caliper, single piston. Since the rear FJ40 axle is a c-clip design, it does move in/out a couple mm's during normal use. A fixed-position caliper cannot allow for that movement, and the rotor will either rub the rotor as it moves in/out that 2mm, or the caliper may not clamp evenly on the rotor causing poor braking. The sliding pin design of the Monte's is the perfect solution to address this issue since the caliper itself moves and adjusts to the rotor location.
Monte Carlos are a sliding pin caliper, single piston. Since the rear FJ40 axle is a c-clip design, it does move in/out a couple mm's during normal use. A fixed-position caliper cannot allow for that movement, and the rotor will either rub the rotor as it moves in/out that 2mm, or the caliper may not clamp evenly on the rotor causing poor braking. The sliding pin design of the Monte's is the perfect solution to address this issue since the caliper itself moves and adjusts to the rotor location.
IMO, for the expense of converting, just track down a canadian fullfloat axle and swap it in. There are a couple "kits" out there too...
Honestly, I've toyed with the fullfloat idea, and opted not to. One reason, I have piles of spare rear semifloat shafts laying around. Additionally, the fullfloat relies on an overall smaller shaft...the semi is 30-spline at the pumpkin but immediately necks up to 1.5" diameter...the fullfloat stays the smaller diameter (1.31 IIRC) throughout it length.
Fullfloats rock for LOAD carrying capacity, but are IMO not an upgrade for offroad use.
Honestly, I've toyed with the fullfloat idea, and opted not to. One reason, I have piles of spare rear semifloat shafts laying around. Additionally, the fullfloat relies on an overall smaller shaft...the semi is 30-spline at the pumpkin but immediately necks up to 1.5" diameter...the fullfloat stays the smaller diameter (1.31 IIRC) throughout it length.
Fullfloats rock for LOAD carrying capacity, but are IMO not an upgrade for offroad use.
only advantage is if you snap an axle you 1 don't loose the wheel, 2 can limp it on the front drive (or 3 wheel drive with a locked rear)
so what is the best swap for the front disks?
Another question about rear disks... Is there a big difference in size between the original drums and the GM disk conversion? Been thinkin about doing that swap on my 75FJ40, but as it is now, my rims have very little clearance on the drums. If I did do the conversion, would I need new rims too??
To Leftartm:
I put GM disks in the rear of my '76 and have "Procomp" 589 (Al 15X10's) and the fit with the caliper was a little tight (maybe 1/8") but so far it hasn't been an issue. I'd have to double check the caliper but it doesn't have the e-brake provision.
To Milesstarkey:
I have a set of knuckles off my '76 left over after moving to 60 knuckles.
The rear disk brake setup can also help keep your rear tire in place if you break an axleshaft. But not near as nice as a FF
I put GM disks in the rear of my '76 and have "Procomp" 589 (Al 15X10's) and the fit with the caliper was a little tight (maybe 1/8") but so far it hasn't been an issue. I'd have to double check the caliper but it doesn't have the e-brake provision.
To Milesstarkey:
I have a set of knuckles off my '76 left over after moving to 60 knuckles.
The rear disk brake setup can also help keep your rear tire in place if you break an axleshaft. But not near as nice as a FF
