Rear Disc Conversion Question

[Kryptoroxx]

FWIW, the Tundra brake mod is really only good at preventing fade and the inevitable warping of rotors. I haven't compared piston sizes, but I suspect they are very very close in size.

To avoid locking up the rear brakes, I think a proportioning valve is a requirement. If you feel adventurous , you could go with an LSPV from a later 4Runner.


Oh, and make sure you get the bleed screws at the top. If not, bleeding will drive you up the wall...

That is some very good information. I know that my 4runner has the smallest brakes that were available. I had 15" rims stock and as always I have the 4 banger engine. I've never had serious problems stopping however I do have a bit of brake dive. It would be nice to balance the brakes out better if possible with the rear setup.

[Kryptoroxx]

I am still working on this. Getting parts together is proving to be easier but more detailed than I thought. I am going to have to get some custom brake adapters made unless someone can point me in the direction of a place to buy brake adapters either online or in the socal area. I was recommended the hose shop in indio I believe for the custom parts but if there is a way for me to piece them together I would prefer that.




Rotors look good. I was trying to figure out whether I could even make a template without slicing the drum brake out. I don't think there really is. However there is a welder close by that has a plasma setup so the 3/8" is a possibility. I am unsure of what the brackets would cost. If I have a template made up out of wood that will work 100% I think it could be a reasonable price. It's the repeat adjustments that would get expensive imo. Thoughts?

[Kryptoroxx]

ha so I have been reading a lot. Seems like everyone loves the conversion off road but no one has figured out the parking brake or soft pedal. Without getting on too high of a soapbox I think a little bit of forethought needs to go into modding your brake system as you guys said. If it's not perfect I would be pissed!

So here's my ideas on perfecting this mod.

1. Proportioning valve- reason for this is obvious as you need to balance the brakes for prolonged use.

2. Residual valve- many have complained about having a soft pedal and or pumping issues. This should help out at least for pumping.

3. Braided steel lines all the way around. Should just help retain all the pressure possible.

4. Mounting the brakes correctly according to their design- I pulled mine from the junkyard and saw how mine were mounted before attempting this. Also saw how the parking brake was plumbed and took the parking brake system as well. When mounted like they are designed things should work more easily (eg parking brake)

5. Sufficient strength in the mount.- I saw some mounts from ruff stuff that were pretty beefy but they are still a bolt on ordeal and it seems the brakes used in their designs don't fit the 4runner very well. Can't have these things shearing while I am driving. 3/8" plate on the design welded on the axle tube with a truss on the backside should do it.

Ran into an interesting comment on the rear disc conversion though. Someone commented that you couldn't put discs on a semi floating axle without messing up the bearings. Didn't make sense to me at all as some production vehicles don't have a full float rear but yet have disc brakes.

Any thoughts? The pile of parts in my garage is growing quite large to minimize down time but I would rather wait and do it right rather than rush and have to do it again.


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[Kryptoroxx]

Well some progress has been made. I now have all the calipers and what I had been worried about is a non issue. I wasn't sure about the clearance between the axle and the panhard body mount but someone took some pics and everything will clear.

My neighbor scored some 13wl calipers in a salvage yard so I promptly traded my painted abs axle tube for the calipers. So far they seem to be in great shape. I was cleaning/polishing them as I am going to paint them. Completely not necessary but I need something to do while the parts pile grows larger.

Tomorrow I should rebuild them and then tape them off for painting.








I thought the pistons looked pretty good but there were a few small knicks but nothing that went across the whole piston. Polishing isn't quite done but I stop working when it hits 95 deg outside (0900-1000). Thankfully when I go to install all this stuff the temp should be staying sub 100.

BTW I have never rebuilt calipers before. Any tips or tricks? I looked up a few threads and everything seems pretty straight forward.

[slomatt]

Rebuilding calipers is pretty easy. There is a trick to removing the pistons. You first take off the piston seals, then put a block of wood into the caliper in front of the pistons. Stick the nose of a blow gun into the brake fluid hole on the caliper and give it a shot of compressed air, this will shoot the pistons out of the caliper. The block of wood is there to make sure they don't go flying out and get damaged or lost, watch your fingers.

- Matt

[troyboy162]

take a couple pictures of the rebuild part if your hands arent too dirty please

[Kryptoroxx]

Will do and thanks for the block of wood tip. I had heard about the compressed air but not that part.

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[Kryptoroxx]

So removing the pistons was a rewarding although violent procedure lol. I couldn't find any wood skinny enough so I used a mouse pad which happened to be laying around. I was able to snap a couple of pics of my attempts at sealing the piston holes since they stubbornly wanted to only come out one or two at a time.




So I used the 7/64" hose to stuff into the holes at the bottom of the piston wells and then I ended up using rags pretty much soaked in brake fluid to stuff in there as tight as possible to seal it well enough to pop the other pistons. Now if the piston directly in front of the brake fluid input blew I would put that back in and hold it with a c-clamp type vise grip as the hose and rags did not work. Once I had a method to my madness I had all 4 out in less than 10 minutes. The first one took me 30. BS'ing and jaw jacking took up another hour and a half at the hobby shop and it was time to leave lol.

So here's the results from the initial breakdown
I have 8 perfectly good pistons and some of my mech friends agreed. They were dirty as hell but they cleaned up pretty nice. I haven't finished cleaning in the picture.


The cups were undamaged and not rusted. I have yet to get the inner seals (these need replacing) out but I have a long weekend and after I rebuild these things the only other thing I have to do is paint them.






On top of that I found out that the hobby shop has a plasma cutter which is great. When the 4runner is down that means I only have to bring the metal stock with me and a few tools of my own but I don't have to get the wife or a buddy to drive me all over the mojave to get the disc mounts done. I should be able to do it all in shop. I might even have access to a mill to help out with the mounts. This has been a good day!

[Kryptoroxx]

Ok so I decided to do my early morning workout and then just smell up the garage until my calipers were done and ready for painting. First thing I did was clean the pistons and check those out.



Next was just general cleaning and removal of the seal inside the piston sleeve.






So now everything was clean and I was satisfied with the condition of everything. I did not see the truck these came off of. I swapped BattleWagon for 'em.

Here's the reassembly of the caliper. There's a little pink package of grease that comes with the rebuild kit and it's a great amount just for the caliper.

Not pictured is the installing of the inner seals as it's hard to see them really. They come pre-greased so they just slip in. Just make sure that you don't roll them.
I actually had to re-insert this one since I forgot the grease. The pistons take a decent amount of grease.


Next comes the rubber boot. Grease this as well and just slip it on. There are two styles that come with the kit. I used the newer one as it looked beefier and installed easier. It is installed in the background as I forgot to take a picture specifically of this step. This is just a trick I used to get the keeper ring (which was not installed when I was dismantling the calipers) It simply slides over the very back part like shown in the next picture



First piston completed.


So after I finished both I was looking at speedy's video comparing it to the job I did and noticed how much shinier he got his. I think he took off whatever coating is there from the factory as well as the dirt and stuff. I decided to coat my calipers with zinc phosphate to increase paint adhering to my calipers. They don't look any different if you ask me but I have great hopes for the paint.



This is the kit part number that I used for the rebuild. All in all it was a piece of cake. Wait till you see what the Ford Mustang rebuild looks like. It makes this look like finger painting.


When will the painting be done?? I have no idea. I purchased the G2 paint and supposedly you can't use it above 70F. At my house it isn't dropping below 100F even at night so I'm not sure what I'm going to do.

[04 Rocko Taco]

Lots of prep work for the paint, I like it.

Last time I painted calipers.... it was Liberal use of carb cleaner and brake cleaner, let it dry, paint.