Rear disc brake conversion?

859Toaster · 05-15-2009, 12:06 PM

Well there is one question we all have. How much?

And you did a great job on the kit. It almost looks stock! And the best part is, it looks to be you can run a stock sized wheel, or 15" wheel.

But thinking about it, can you still run low offset wheels with these? Like a 15X8 +0 or 15X7 +10

PCH · 05-15-2009, 01:01 PM

That looks like a very good conversion to me. Glad to hear it tested fine.
Few questions i have:
Is the parking brake strong enough to completely lock rear wheels?
Have you tried locking your brakes on wet pavement to verify proper ABS performance?
Do calipers require any additional machining to fit, or it it a straight bolt-on?
Other than brackets and fittings that you may be selling as DIY kit, are other parts easily obtainable? (Calipers, rotors and replacement pads)
Seems easy to convert to rear disks using what you've developed. Major props, man

Rcurry23 · 05-15-2009, 04:19 PM

Quote:

Originally Posted by PCH

That looks like a very good conversion to me. Glad to hear it tested fine.
Few questions i have:
Is the parking brake strong enough to completely lock rear wheels?
Have you tried locking your brakes on wet pavement to verify proper ABS performance?
Do calipers require any additional machining to fit, or it it a straight bolt-on?
Other than brackets and fittings that you may be selling as DIY kit, are other parts easily obtainable? (Calipers, rotors and replacement pads)
Seems easy to convert to rear disks using what you've developed. Major props, man

Thanks for the kind words. I was pretty happy with the outcome! As far as the parking brake, no you can't lock it up. And I believe even if you tried to adjust it at the handle you would actual adjust it to much, to where it was applying some of the parking brake, without pulling the handle. Then you may be able to lock them up, but why??? And as far as the wet/dry testing. Yes. I drive my xB everyday. Hot, cold, snow, rain....whatever the weather brings me. Now I am no engineer so my terms may be wrong, but when you hit the brake hard and fast, you get the pulsating feeling like your going over railroad tracks. Not sure the correct term for that but thats what it does. It doesn't lock up into a slide! As far as the parts needed for the kit. Yes, there is some modifications that have to be done. Like the caliper. When it comes in the mounting bracket plates where the bolt holes are is very thick. That has to be machined down to .680 to fit between the kits mounting brackets and the rotor. Also the new calipers don't come with the e-brake mounting tab. And the salvage ones I was buying up to get my core charges back. The mounting bracket on those were always rusted, so I also had new ones of those made. Because they are unavailable for sell in the US or Japan! Then the rotor used, to fit on the xB hub the pilot has to be skimmed, and I mean skimmed. Very little material has to be removed from the pilot hole of the rotor. Now on to the xB hub. The way its made it has like 4 spokes. Each of those spokes have to be ground on or machined off some to fit inside the rotor hat. The way I got the e-brake to work is. You cut the end of the stock cable off, pull the cable out from the inside of the car. Then install my machined parts on the cable and slide it back through from the outside back of the car. Then on the inside I made cable stops to lock onto the cable to allow for adjustment, or just to give the cable its other end back!! Its kinda hard to explain so here are some more pictures. I have lots of pictures!!!! I just don't want to bore anyone with a bunch of pictures.

Caliper modified. Notice the area where the mounting holes are have been machined down.

xB hub, as you can see….. Not fitting

Hub on machining fixture

After machining

And hub mounted in hat

cable and assembly on rear end

Cable assembly

Cable cut

Assembly cut

Machined parts installed

PCH · 05-15-2009, 04:55 PM

Thanks for your answers!
Pulsating pedal when you are trying to lock brakes is an indication that ABS is functioning. So that's a plus.
Other than cutting parking brake cables (which are replaceable) there are no irreversable modifications to the car. A good thing also.
I like how it's done. I don't know how i would go about having hubs and calipers machined if you were to provide just the brackets and hardware, but i think i could find a shop to do that- pretty basic stuff.
I honestly think the stock brakes on xB perform fine, but having discs would look much better. Did you feel any difference after the conversion?
I like to be sure i can hold the car on a steep incline with just parking brake engaged- just a safety issue.
Rep points for developing a functioning conversion, hope you sell a few more. Marking this as an option for the future.

Rcurry23 · 05-15-2009, 06:10 PM

I will try to find the steapest incline I can find around here and take a picture of it. I did this once before but never took a picture. I'll try to do that this weekend!

859Toaster · 05-16-2009, 12:17 AM

(why do I see a scene from the Top Gear episode where they are trying to prove that 80's British cars, were good cars.... It was a epic fail)...

But all joking aside now....

I don't know about PCH's driving style when he does autocross, but sometimes the lay outs require a little e-brake slide. Oh, and of course, winter drifting fun. lol. Those are the only reason I'd need full rear lock. (gotta love having an auto for that reason).

But yeah, minus the mild machining that needs to go into them, solid conversion.

gothbox · 05-16-2009, 12:19 AM

Quote:

Originally Posted by 859Toaster

(why do I see a scene from the Top Gear episode where they are trying to prove that 80's British cars, were good cars.... It was a epic fail)...

one of the MANY great episodes, LOL

thread jack over.

PCH · 05-16-2009, 02:46 AM

Quote:

Originally Posted by 859Toaster

I don't know about PCH's driving style when he does autocross

My style is mild but i dont like loosing what the manufacturer provided. If the parking brake alone should hold the car on the incline, then it's gotta be there if i need it. As long as it's at least as good as stock it's good enough.

Rcurry23 · 05-16-2009, 12:54 PM

Quote:

Originally Posted by PCH

My style is mild but i dont like loosing what the manufacturer provided. If the parking brake alone should hold the car on the incline, then it's gotta be there if i need it. As long as it's at least as good as stock it's good enough.

Does your stock e-brake lock up? Mine didn't when I bought mine. I even took it back to them and told them it needed adjusting. They said they did, but it still didn't lock up. To me it is as good, if not better than what it was when I bought the xB.

crxgames · 05-16-2009, 01:05 PM

Mine does, but I have to pull it very tight. It will hold the car on a fairly steep incline.

Rcurry23 · 05-16-2009, 01:23 PM

Quote:

Originally Posted by crxgames

Mine does, but I have to pull it very tight. It will hold the car on a fairly steep incline.

Well, if thats the case then maybe I wasn't pulling tight enough on it, and may still not be. One more thing to try this weekend!

859Toaster · 05-16-2009, 02:20 PM

brake drums aren't very good for locking up. Because they are pushing out, clamping down. If the drums were bigger, and the shoes were bigger, it would probably lock better.

Rcurry23 · 05-19-2009, 06:00 PM

Just wanted to let anyone know who may be interested that I am re-working the pricing. Some of the components I buy went down, so I thought I would pass it along. Give me a few days and I should have some numbers!

whitej47 · 05-20-2009, 05:10 AM

Give us a price on the "nuts and bolts" kit if you got one. Thanks

Randy · 05-26-2009, 08:18 AM

Yeah I'm definitely interested in the new price for this kit. I've been wanting to do a rear disc conversion for a while now. I'm tired of seeing those tiny little drums in the back.

Rcurry23 · 05-31-2009, 09:24 AM

Ok, I have three different ways to sell these. Complete kit with hubs, complete kit without hubs, and just the hardware to do the kit yourself. I can't post prices in the post, so PM me if your interested!
Thanks

kngrsll · 06-05-2009, 03:54 PM

i wonder if this will fit a yaris

Myopic · 09-11-2009, 12:25 AM

I bought the rear disc brakes which Zeel0 posted about being listed on eBay. As best I can identify the brakes, they are from a 2003 Toyota iSt NCP61 even though the seller showed them as being for a NCP60.

All references I can locate do not indicate the NCP60 had rear discs, even as an option. Someone better informed may know more about options for the iSt.

I reconditioned the brakes and have been running them for a while now with perfect performance of the service brakes and the parking brakes.

The salvage yard personnel cut the parking brake cables and the rubber flex hoses in half when removing the brakes. To use the iSt brakes on my 2005 xB I only had to make two minor modifications to my stock parking brake cables, one easy modification to the iSt backing plates to mount the xB parking brake cable, and had to buy a set of flex hoses.

The iSt rotors, calipers, caliper mounting plates, and my xB's axle hubs, did not have to be trimmed, ground down, pilot opening increased, or otherwise modified to be installed. These are Toyota parts and they fit perfectly in stock condition.

Total investment for everything was under $600, including the shipping from Hong Kong to the US and reconditioning.

To answer Mikesbluexb's original question from the start of this thread; I used the parts I had in hand for the iSt disc brake assembly, and compared them to illustrations for a 2005 Toyota IST NCP61-HHPGK on ToyoDIY.com. They appear to match a 2005 Toyota Yaris SCP12R-CHMGKW as an excellent donor car for which there are parts available from some US Toyota dealers. Here again, someone else may be better able to validate, or to negate, this comparison.

But buying them new would not be cheap. The best prices I found for new parts were at ineedtoyotaparts.com and they came to just under $1400. Several US dealers showed having the parts, although not all dealers listed them. If anyone wants the list of Toyota Yaris part numbers and names I would be glad to post them.

As anyone who has been following rear discs conversions for the Gen 1 xB might guess, the only 2005 Yaris part which I cannot find in the US is the parking brake cable. But even with the modification to my xB's stock cables, they can be returned to use on the stock drum parking brake if desired.

My apologies for the long posting.

O6er · 09-14-2009, 10:22 PM

I have been seeing more and more ofthe 1st gens with discs. There has got to be some supplier somewhere. I am going to check out Shermans later this week.

15yroldSciontist · 09-21-2009, 09:33 PM

Subscribed..