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TR4/4A Interesting problem w/ TR4A brakes

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tdskip

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So the passenger side went together no problems, but the driver side brake rotor is rubbing on the Toyota caliper. Same brake rotor manufacturer and part #, and same brake caliper source and part #.

It appears that the rotor is slightly out of round since it doesn't drag consistently all the way across. Of course the rotor may not be bolted on square either, which I need to go check, but anyone else had an issue like this?
 
Could there be a problem with the bearing races, or the seal not seated correctly(to thick of a seal). 1st of all I think I would check the rotor for trueness with a dial indicator. Spin the rotor and check for runout.
 
Turns out that I have a COP (current owner problem). I ordered the wrong Toyota calipers. LOL.

The bolt pattern is correct but the shape of the caliper is slightly different and it rubs. Why one side fit and the other didn't is still a bit of a mystery. Keith may have nailed it.

Make sure you have your Toyota truck model and specification right!
 
Will you post some pictures when you get it right? I hve always been curious about this conversion. Actually, what I really want to know is if it stops any better...
 
Will do Ian. I did the '74 TR6 (with correct parts) and it's a snap. Ted at TSI carries the brake lines you need.
 
Thanks. Does it improve braking performance, or is it simply a nod to more modern and cheaper components?
 
tdskip said:
Will do Ian. I did the '74 TR6 (with correct parts) and it's a snap. Ted at TSI carries the brake lines you need.
Click to expand...

I did the conversion and used the instructions found on the VTR site brake conversion You do need to buy the special caliper bolts from a later TR6 that have a metric bolt shank and standard threads. This will properly hold the caliper. The other specialty bit is the brake hard line that runs between the caliper and the flexible brake lines. The caliper is metric and the Triumph brake lines are standard so a conversion is needed. Ted at TSI does sell the conversion bits and also stainless flex lines as well. The article also explains that you need a trim a bit of the Triumph backing plate and shows you where to trim.
I went the DIY route. I took a Toyota caliper to an auto parts store and bought a couple feet of brake line with the correct metric ends already installed. I cut the line in half so that I would have 1 line for each side of the car. I bolted the calipers onto the car and formed the hard line to more or less match the way the old ones routed. I then cut the line to fit. I cut the flare nut off my old Triumph caliper hard line, slid it on the new line and flared the new line. Note that its easier to flare a straight line than a curved one so save yourself some room for flaring.

As to improvement in braking? I don't know, I'm just getting this car onto the road. All the hydraulics needed rebuilding. Braking on my 6 isn't spectacular so I thought I'd try something different this time around. From what I've read, people argue both sides. One side says that it makes no improvement. Another side says a 20% improvement. All I see it that it looks like the Toyota pads are bigger than the Triumph pads and there are now 4 pistons instead of 2 on each side. Seems to me like something ought to be work better. The other thing I did was to replace the rear wheel cylinders with the bigger ones from a Morgan or Sunbeam. Everyone seems to agree that change makes a difference.
 
tdskip said:
Turns out that I have a COP (current owner problem). I ordered the wrong Toyota calipers. LOL.

The bolt pattern is correct but the shape of the caliper is slightly different and it rubs. Why one side fit and the other didn't is still a bit of a mystery. Keith may have nailed it.

Make sure you have your Toyota truck model and specification right!
Click to expand...
Tom, did purchase of another set of calipers fix this problem? I posted same problem a few months ago to the forum and couldn't resolve why my drivers side rotor wasn't centered in the caliper. So, I took the caliper bracket to my friendly local machine shop and they skimmed about 20 thousands off it and the rotor is right smack dab in the middle of the caliper now.

Don't tell me I just purchased the wrong calipers from RockAuto? This was a Toyo conversion on a TR3 which is a bit more difficult than on a TR6. On the TR3, I had to make quite a few cuts to the backing plates (much more and different than in the VTR web article). I made metric to standard hard line pigtails and TSI Ted made me some custom braided steel brake lines. Art has previously posted some photos of the brackets that he fabbed to hold the braided steel brake lines. I also had to use a TR6 caliper bracket, of course.

Pat
 
Here are a few images of my Toyo brake challenge.

IMG_9079.jpg


IMG_9078.jpg


IMG_8372.jpg


IMG_8356.jpg


TR3TR6Caliperbracket.jpg


and photo from Art on brake line routing on TR3
brakelinerouting.jpg
 
So there is more than one way to do this as it turns out.

The calipers that I used on the TR6 are truly bolt on. The part numbers from RockAuto are A-1 Cardone are 17820 and 17821 and they come fully loaded.

Other SR5 brakes can be made the fit, and it appears that the ones I ordered are very similar to the ones you used. I had the exact same rubbing issue as you did Pat, and I reverted back to the A-1 Cardone part numbers references above.

I believe that the difference between the 1984 and 1984 Toyota SR5 and/or trim differences between 2 and 4wd calipers are the difference.

In my "experiment" once side fit and I could have shaved the other side to have, but decided to stick to the knitting so I had the same thing on each of the cars.

I may still use the calipers I ordered by mistake on the solid axle TR4a when the time comes.

The A-1 Cardone calipers should be here today or tomorrow and I'll report back.
 
This is really good info for anyone contemplating this upgrade. Thanks Tom. Let us know how the new A-1 Cardone calipers fit. I would have preferred your solution (use different calipers) but I suppose now that my caliper fit the rotor, I'm in good shape!

pat
 
OK - so the new caplipers from RockAuto just showed up. Fit the passneger side - no issues, fits great. But the driver's side was the issue... stay tuned.
 
Just went to fit the drivers side and......
















it fits fine. So Pat maybe you just got a bum set or a slight difference in the caliper based on having the Toyota model a touch off.
 
Glad to hear they fit. I'll go home tonight and check the box and see what year/model Toyo truck they were designed for. This might help others in the future.

Pat
 
DanB said:
Sooooo......the Toyota rotors aren't vented? Then what is the point?


Dan B.
Click to expand...

The conversion as discussed here pertains to using the stock Triumph rotors with Toyota truck calipers. You can upgrade to Toyota Cressida vented rotors but they need some machine work done to them in order to fit the Triumph.
 
DanB said:
I see. Well, do the above calipers fit with the vented rotors? Are they wide enough?
Click to expand...

Apparently not. I have not gone the vented route myself but the instructions here say that you need 4-Runner calipers with the vented rotors.
 
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