Disc brake conversion, again... (1 Viewer)

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Hello All. Done and the brakes work awesome, thanks for all the help.
Just want to summarize the parts I used in case it helps anyone.

To use the FJ80 booster, I had to grind the Clutch slave cylinder slightly. I did this with an angle grinder while it was installed.
I also had to slot the bolt holes in the firewall slightly. Just another 1/8" or so toward the passenger side. Not a big deal, and it all fit in there, snugly.

-FJ80 1994 non-ABS Master Cylinder. Advics BMT090, from Rockauto 68 bucks

-FJ80 1994 power brake booster. Ebay $75 (this seller sent me the wrong booster, but when I informed them, they sent me the correct one ASAP, with no hassle. Now I have a spare Tacoma booster)

-Already had a Wilwood disc kit on front, but I ended up replacing the calipers because I noticed a leak and some wear on a piston.

-Used Poser's rear disc kit. Rotors, brackets, soft lines, and seals. Great quality and price, highly recommended.

-Used Delco rebuilt rear calipers for 1984 Monte Carlo, from Rockauto, 18FR626C, 18FR625C , for about $30 each. And Delco semi metalic pads for about $30

-Used copper-nickel 3/16 brake tubing that came with the correct 10mmx1.0 inverted flare fitting from Amazon. This stuff couldn't have worked any better. 30 bucks
25 ft. Copper Nickel 3/16" Brake Line Tubing w/metric brake Line invert flare fittings. 10 x 1 mm (Pack of 10 fittings)


-Titan inverted flare tool. This worked perfectly with the copper-nickel brake line. And the existing steel line. 43 bucks
Titan 51535 3/16-Inch Double Flaring Tool


-New steel braided lines from the frame to the axle, from SOR. Nice parts. 2 @ $30 each. arg...
PN 086-31A-S , 086-32C-S

-Tilton Proportioning valve from Pegasus Auto. 93 bucks. I went with this one because it had 3AN connectors, and I could find the correct 3AN to 10mm inverted flare fittings. (yes, a little OCD I realize)

- (2) 3AN to 10mm inv fittings, from Proportioning valve to Toyota brake lines. $12


One thing worth mentioning, when I had the rear diff cover off, to remove the axles, I noticed excessive slack in the spider and side gears. Pardion had a good used set of gears for a great price. And I replaced the thrust washers with new ones from CuriserOutfitters. All squared away on the diff.


Also, someone mentioned routing the proportioning valve.
I was able to carefully cut, reroute, and flare the existing rear line at the Master Cylinder end, and work in my proportioning valve. I made an aluminum L-bracket to support the Proportioning valve, that bolts onto the new brake booster. It's probably not recommended to flare existing lines? But I practiced a bunch and it seemed to work well with no issues, so I went ahead. No leaks. In the first pic you can see how I cut and bent the existing line to work with the proportioning valve.

cut exiting line
20200817_165924.jpg


ran new line from M/C to proportioning valve
20200824_135215.jpg


tight fit.
20200824_140203.jpg


existing splitter to new brake line
20200817_111212.jpg


20200810_192312.jpg


Hope this helps!
 
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Joined
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Arizona
Looks great! I’m looking to do something very similar. I tried to send Poser an IM but it’s not letting me. (Perhaps I haven’t posted enough times for that privilege?) I would like to buy his rear brackets and rotors as well. Can you suggest another method to contact him? Thanks!
 
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Thanks. The website is under construction though. Not seeing a contract link or anything. Just links to other vendors/ manufacturers. I also tried calling the phone number but got an "all circuits busy" message.
hmm...
I bet if you reply to this thread you'll get a response.
Good luck.
 
Joined
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California
The non-ABS FZJ80 master cylinder comes stock with the right residual pressure for discs on all four wheels; if you use this master then you won't have to change or worry about residual valves.
Which part number did you use, if I may ask? 47201-60540 (BMT303)? I believe that is the correct part number for a 8/92 - 5/94 non-ABS FZ80, and that is what I see a lot of people on the forum recommending. However, both Cityracer and JT Outfitters say that the 47201-60551 (BMT-046) is the one to use with 4 wheel disc conversions, but it is listed for vehicles WITH ABS.

To further complicate that, I just read that you don't want to use an ABS M/C without an ABS module inline, something about retracting force on the calipers.

I'm just trying to make sure I get the right M/C from the start. I have a '73 40, and I just did a minitruck front disc conversion using 60 rotors and V6 calipers, and also rears with Monte Carlo calipers. I've read that not all FZ80s had discs in the rear, so the later 60551 M/C for 4 wheel disc vehicles seems like it might be more appropriate (except for the ABS question). I'm wondering if running that one instead of the 60540 might reduce or eliminate the need for a proportioning valve.

Just looking for some clarity.
 
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-Used Poser's rear disc kit. Rotors, brackets, soft lines, and seals. Great quality and price, highly recommended.

-Used Delco rebuilt rear calipers for 1984 Monte Carlo
I agree on Poser's kit. I just did mine over the weekend, and it couldn't have gone better.

One question: Did you have to grind the calipers to get them in the brackets that way? I wanted to use the orientation that you did, but the calipers would only fit into the brackets one way, due to a nub on the casting of the caliper. If I flipped the bracket over from the orientation you used, it worked great, without any grinding, and it ended up looking like this:

Side View.JPG


In retrospect it is not a problem, and it allowed me to route the hoses around the back and over the top of the axle housing. I am going to weld the tombstone tabs right to the top of the housing just inboard of the brackets. So the hoses will be well-protected. I suppose the calipers are in a slightly more vulnerable location than on yours, but I don't do any serious rock crawling, and as you can see it is a spring-under and I am not planning on changing that.
 

Drake2

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I plan on doing something like this in the near future as well. My question is why go through all the work to end up using Monte Carlo car calipers? It would seem to make more sense to make a bracket that would use the same calipers as the OEM later model 40's use on the front. Unless I am missing something here, we can make a bracket to use Monte Carlo caliper then we can make a bracket to use Toyota caliper. Maybe someone has tried this and for some odd reason that I am not aware of they are not a good option. If this is the case, it would be great to have some feedback on why.
 
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I plan on doing something like this in the near future as well. My question is why go through all the work to end up using Monte Carlo car calipers? It would seem to make more sense to make a bracket that would use the same calipers as the OEM later model 40's use on the front. Unless I am missing something here, we can make a bracket to use Monte Carlo caliper then we can make a bracket to use Toyota caliper. Maybe someone has tried this and for some odd reason that I am not aware of they are not a good option. If this is the case, it would be great to have some feedback on why.
Even with use of "just" the Monte Carlo calipers, you will see many people reporting the need to add a proportioning valve to keep the rears from locking up. If you put even bigger calipers in the back, I would think that problem is going to be magnified. Plus, the Monte Carlo calipers are available everywhere, and cost about $22 each. Personally I am stoked that the whole thing can be done with Chevy parts.

Just my impression.
 

Drake2

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Even with use of "just" the Monte Carlo calipers, you will see many people reporting the need to add a proportioning valve to keep the rears from locking up. If you put even bigger calipers in the back, I would think that problem is going to be magnified. Plus, the Monte Carlo calipers are available everywhere, and cost about $22 each. Personally I am stoked that the whole thing can be done with Chevy parts.

Just my impression.
I'm not knocking the system in any way and I agree with you on the ease of putting the system together with those parts for a really affordable pricetag. I know there are lots of people running this set up for sure and they all seem to like it. 👍. I'm thinking that when it comes time for a 4 wheel brake job I would rather order 2 left calipers of the same part number and 2 right calipers of the same part number all for the same application. Just seems like it would be easier to keep track of what you need when it comes time to place orders.
 

pjohnson

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I agree on Poser's kit. I just did mine over the weekend, and it couldn't have gone better.

One question: Did you have to grind the calipers to get them in the brackets that way? I wanted to use the orientation that you did, but the calipers would only fit into the brackets one way, due to a nub on the casting of the caliper. If I flipped the bracket over from the orientation you used, it worked great, without any grinding, and it ended up looking like this:

View attachment 2608691

In retrospect it is not a problem, and it allowed me to route the hoses around the back and over the top of the axle housing. I am going to weld the tombstone tabs right to the top of the housing just inboard of the brackets. So the hoses will be well-protected. I suppose the calipers are in a slightly more vulnerable location than on yours, but I don't do any serious rock crawling, and as you can see it is a spring-under and I am not planning on changing that.
Are the bleeder valves on top of the caliper?
If not, proper bleeding is almost impossible.
 
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The bleeders on mine are at the top. Part of my point was that the Monte Carlo calipers that I purchased from O'Reilly Auto would not fit into the Poser bracket in the orientation BrianSanDiego used. In fact that was the first orientation I tried. There was a nub in the casting that ran into the bracket and disallowed installation in that orientation.

As soon as I flipped the bracket over, the caliper dropped right in. This struck me as unusual because Brian's orientation was the same as what Poser used in his thread detailing the installation (which is why I tried that first). However in retrospect maybe Poser ground the nub off, or it didn't exist on the calipers that he purchased.

Here's the pic from Poser's thread. On my calipers, the nub would be in the upper left of the caliper opening, where the long inner radius appears, just next to the bleed screw. My choices were to either grind off the nub, or flip the bracket over. When I flipped the bracket over, the nub tucked right into that more squared-off corner that you see at the bottom in this picture. In fact it looked like it was cut differently in order to accommodate the nub.

In any case, it worked, and I am going to roll with it, unless someone here can tell my why that would be a bad idea.

1615328587828.png
 
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One question: Did you have to grind the calipers to get them in the brackets that way? I wanted to use the orientation that you did, but the calipers would only fit into the brackets one way, due to a nub on the casting of the caliper. If I flipped the bracket over from the orientation you used, it worked great, without any grinding, and it ended up looking like this:
Howdie..
Yes I did have to grind that nub off the caliper. My train of thought was, that I wanted the hardware as high as I could get it. That may not be a concern for many. Grinding was a little concern too, as the sealing surface for the brake line is next to the nub, so one slip of the grinder and your caliper might be FUBAR. (one trick I used, pull the brake line port plug out, add a washer the diameter of the sealing surface, and reinstall the plastic plug. The washer will now protect the sealing surface while you grind). Also that nub help keep the brake line from getting pushed and rotated around the bolt. With the nub gone it's hypothetically possible for the line to get bumped and loosen the hose bolt.
There is something to be gained by not grinding that tab off.

Edit:
You were asking about M/Cs. FWIW, mine really needs the proportioning valve and I even have Wilwood front brakes, which supposedly work stronger than Toyota front.
Gentle to medium braking is fine without the Prop-valve, but when you get on 'em, the rears would lock right up without much effort.

Brake bias is a function of piston sizes. (you probably know this) In a factory vehicle the front and rear piston diameters will be designed to give the desired front/rear bias. With our rear disc conversions, that all goes out the window. So a proportioning valve is required to compensate for the incorrect piston areas. I'm not sure a master cylinder can adjust for these issues. Maybe there is a best MC though. ...not sure.
B.
 
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1911

chupacabra
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Which part number did you use, if I may ask? 47201-60540 (BMT303)? I believe that is the correct part number for a 8/92 - 5/94 non-ABS FZ80, and that is what I see a lot of people on the forum recommending. However, both Cityracer and JT Outfitters say that the 47201-60551 (BMT-046) is the one to use with 4 wheel disc conversions, but it is listed for vehicles WITH ABS.

To further complicate that, I just read that you don't want to use an ABS M/C without an ABS module inline, something about retracting force on the calipers.

I'm just trying to make sure I get the right M/C from the start. I have a '73 40, and I just did a minitruck front disc conversion using 60 rotors and V6 calipers, and also rears with Monte Carlo calipers. I've read that not all FZ80s had discs in the rear, so the later 60551 M/C for 4 wheel disc vehicles seems like it might be more appropriate (except for the ABS question). I'm wondering if running that one instead of the 60540 might reduce or eliminate the need for a proportioning valve.

Just looking for some clarity.

This is the exact part I bought from Cruiser Outfitters:

Brake Master Cylinder - Fits 8/1992 - 5/1994 8x Series Without ABS (BKN60540N) - https://cruiserteq.com/brake-master-cylinder-fits-8-1992-5-1994-8x-series-without-abs-bkn60540n/

It works perfectly; a great improvement in braking over the stock master cyl. I am using it with a Wilwood proportioning valve.

 
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Yes I did have to grind that nub off the caliper. My train of thought was, that I wanted the hardware as high as I could get it. That may not be a concern for many. Grinding was a little concern too, as the sealing surface for the brake line is next to the nub, so one slip of the grinder and your caliper might be FUBAR.

We're talking about different nubs. I'm familiar with the situation you're referring to. Fortunately the style of hoses that Poser included with his kit has an angle right where it leaves the caliper, and that angle is sufficient to get the hose over the ridge without grinding. At least I think it is, I'm not 100% positive, because I ended up coming straight off of the caliper where the gap is, towards the back of the vehicle, where it will wrap up and around the axle to the top of the axle housing, where I will weld a tab.

If you look at the latest photo I posted, which I lifted from a RDB install thread started by Poser, the casting nub on my calipers would be just to the left of the bleed screw, at about the 9:30 position, and it bumped right into the large inner radius of the bracket. In order to keep the bleed screw at the top, I had to flip the bracket over; you'll see it has a sharper radius on the other side of the opening, and the nub tucked right into that, which leads me to believe that may have been intentional.

Of course that leads to the caliper being lower, as in my earlier photo of my actual installation. Yeah, I would have preferred it be higher, but I am not a hard core off roader, and these calipers are on $22, plus I have the stock spring under, so there's a lot of clutter down there anyway.

Thank you also for the master cylinder insights.
 
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This is the exact part I bought from Cruiser Outfitters:

Brake Master Cylinder - Fits 8/1992 - 5/1994 8x Series Without ABS (BKN60540N) - https://cruiserteq.com/brake-master-cylinder-fits-8-1992-5-1994-8x-series-without-abs-bkn60540n/

It works perfectly; a great improvement in braking over the stock master cyl. I am using it with a Wilwood proportioning valve.

Thank you for the info. I have conflicting info on the M/C you're referring to here. I saw at another place on this forum that this was for non-abs disc/disc, but CityRacer's site says it is disc/drum. Furthermore, CityRacer specifically recommends the 60551 for disc/disc installations, and that is the only one on their site for which they make that recommendation. That leads me to wonder if there is something different about it, and whether it might possibly preclude or minimize the need for a proportioning valve.

I'm far from a Cruiser guru, but I have gathered that there were some disc/drum 80's. Plus the whole ABS/non-ABS question keeps nagging me.

I appreciate all of the feedback!
 

1911

chupacabra
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Thank you for the info. I have conflicting info on the M/C you're referring to here. I saw at another place on this forum that this was for non-abs disc/disc, but CityRacer's site says it is disc/drum. Furthermore, CityRacer specifically recommends the 60551 for disc/disc installations, and that is the only one on their site for which they make that recommendation. That leads me to wonder if there is something different about it, and whether it might possibly preclude or minimize the need for a proportioning valve.

I'm far from a Cruiser guru, but I have gathered that there were some disc/drum 80's. Plus the whole ABS/non-ABS question keeps nagging me.

I appreciate all of the feedback!

Also, if it wasn't obvious from previous posts, I am using that master with disc/disc i.e., discs on all four corners. Monte Carlo calipers in the rear and stock 1980 FJ40 calipers on the front.
 
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I took a picture this morning to illustrate the issue I was having. As you can see, there is a rather large protrusion in the casting on the caliper. With the brackets in this orientation, the protrusion is accommodated. If I flip the bracket over, the nub on the caliper won't clear the bracket.

These are the 18-4071 and 18-4072 calipers, purchased at O'Reilly Auto. They were for an '86 Monte Carlo.

I was wrong about the nub being in a different place than it others' pictures. It's just bigger on mine than on the others.

Anyway, it seems to work just fine like this, and note also that the angled banjo end on the hoses from Poser allow them to route nicely under the axle, and I'll wrap them around the back and up onto the top, where I'll weld a bracket. So the hoses themselves ought to be quite well protected.

IMG_0796.JPG
 

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