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TR6 Toyota Caliper Conversion
- Thread starter glemon
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OP
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I put the new calipers and rear wheel cylinders on, think I have a problem, the new cylinders looked smaller (at least externally) in diameter, not larger than the old ones, of course I was out in the garage, greasy and hot, halfway through the job, and I put them on anyway, because at the time I was not absolutely sure if they should be bigger or smaller, I was assuming bigger, but didn't know the base size of the TR250 item off the top of my head. The brakes a spongy like they need to be bled again, which I think is a separate problem, but I don't think I got bigger diameter rear wheel cylinders, got a Morgan part that was supposed to be right, I need to take one side apart, at least to the point where I can measure the internal diameter of the cylinder, rats.
Update: I looked at the old rear wheel cylinder, the casting is much much bigger than the inside diameter, so perhaps there is no problem with the new rear wheel cylinders, so will double check the adjustment of the rear brakes, then rebleed if needed and hope the pedal firms up.
Update II: Never mind on the cylinders, they are bigger, just a thick wall on the old rwc and a thinner one on the new one, still have a spongy pedal that goes to the floor, will deal with it tomorrow.
Update: I looked at the old rear wheel cylinder, the casting is much much bigger than the inside diameter, so perhaps there is no problem with the new rear wheel cylinders, so will double check the adjustment of the rear brakes, then rebleed if needed and hope the pedal firms up.
Update II: Never mind on the cylinders, they are bigger, just a thick wall on the old rwc and a thinner one on the new one, still have a spongy pedal that goes to the floor, will deal with it tomorrow.
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Tybalt
Jedi Warrior
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That's why I mentioned earlier that the rear cylinder was the same basic casting which allows it to be a drop in substitution for the TR rear wheel cylinder.
Remember that both the Toyota calipers and the larger rear wheel cylinders both have larger fluid volumes than the pieces you have removed. The pedal will be "longer" and bleeding will be a bit more tedious. Make sure that you don't let the reservoir run dry and suck in air, also make sure that you center the DPWA piston for the brake system. Another thing that can cause an issue is excessive bearing play up front. This can "knock" the pads back so your first hit of the pedal will mostly serve to move the pads back to the disc. If you get everything dialed in, it will work, but you will have a longer pedal with the Triumph master cylinder, there's just no way around that since you are moving more fluid.
If you just can't take the longer pedal, I have heard of people using a master cylinder from an XJ6 (the last one before the XJ40 designation XJ6). I have no experience doing that, just heard of it being done.
OP
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I bled again tonight, it seemed like it was all better, I did get a lot of air out of the right rear wheel cylinder and none out of the rest, last night when I did the work I tried to seal off the lines as quickly as possible so I wouldn't use as much fluid, wouldn't have to bleed as much, and wouldn't make a huge mess, so assuming I didn't loose much fluid or create many air bubbles I didn't do a real big bleed last night, 5-pumps on each wheel.
So after tonight's bleed and getting air I waited a while and pressed again, and still had a good pedal, things seemed much better than last night, then I went for a drive, they are a little better, but the pedal still gets very low very quickly, and the braking force is not good at all, but it pumps up. I am wondering about the pads getting pressed back or something like it, when I fit the calipers I noted their "natural position" was quite loose on the disk, like they were made for a vented disk with more width, wondered if the pads aren't backing off and giving me excess travel, I think I could pump up the brakes like I had air in the system as well.
Second source of possible problems, the rear cylinder mount the pin or fulcrum for the emergency brake, the casting on the new cylinders had the indent for these in a slightly different place, throwing my rear brake adjustment off, tried to adjust but still may be out of whack.
Third, still could be air in the system, but I am pretty sure I bled it out, I pumped a lot of fluid through the system, and all lines were running with no air for several pumps before I closed them off and went to the next one, and, although I almost forgot a couple times, I never did let the M/C get dry, been there, done that, not much fun.
Everything was working great, brakewise and otherwise on the car before I started, no leaks, no air, when I put the new parts on I did my own flare in the front brake lines, and triple checked to make sure they didn't leak, as well as checking the reattachment to the rears.
I thought about fitting the fronts first, checking it all out, then going to the rears, but thought I would be efficient and do it all at once, but in hindsight this would have been much easier to diagnose had I done one end at a time.
So after tonight's bleed and getting air I waited a while and pressed again, and still had a good pedal, things seemed much better than last night, then I went for a drive, they are a little better, but the pedal still gets very low very quickly, and the braking force is not good at all, but it pumps up. I am wondering about the pads getting pressed back or something like it, when I fit the calipers I noted their "natural position" was quite loose on the disk, like they were made for a vented disk with more width, wondered if the pads aren't backing off and giving me excess travel, I think I could pump up the brakes like I had air in the system as well.
Second source of possible problems, the rear cylinder mount the pin or fulcrum for the emergency brake, the casting on the new cylinders had the indent for these in a slightly different place, throwing my rear brake adjustment off, tried to adjust but still may be out of whack.
Third, still could be air in the system, but I am pretty sure I bled it out, I pumped a lot of fluid through the system, and all lines were running with no air for several pumps before I closed them off and went to the next one, and, although I almost forgot a couple times, I never did let the M/C get dry, been there, done that, not much fun.
Everything was working great, brakewise and otherwise on the car before I started, no leaks, no air, when I put the new parts on I did my own flare in the front brake lines, and triple checked to make sure they didn't leak, as well as checking the reattachment to the rears.
I thought about fitting the fronts first, checking it all out, then going to the rears, but thought I would be efficient and do it all at once, but in hindsight this would have been much easier to diagnose had I done one end at a time.
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OP
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The rear brake adjustment and alignment got out of whack when I put the new rear wheel cylinder on, and although it does self adjust back into alignment to some extent with use, apparently it hadn't when I readjusted the rear shoes, I had particular issues putting the right rear drum back on, and backed the adjustment off quite a bit to get it back on, I thought I had adjusted it ok, but apparently I hadn't. I now get good stopping, but the pedal does go down quite a bit, which is a little disconcerting, and it certainly is sensitive to everything being right and appropriately adjusted with the whole system.
It does seem to stop pretty well, didn't do any empirical test like buckeye triumphs, but seems to stop better. I will see if I get used to the pedal being low, I would say instead of getting impending lockup at about 1/3 or pedal travel with the stock brakes it feels more like 2/3 travel with the upgrade, but they do pull it up sharply when applied, I have big tires (205/65) so having the big brakes to go with them seems to make sense. Will see if I get used to the new feel, and also if I can adjust a little more play out, but I think I may have done about all I can with it.
The presumably larger bore M/C conversion does intrigue me though, but I am just going to drive it a little, maybe I will get used to it. The do pull the car down from speed very well, I got semi-metallic pads, which always seem to get a little sharper bite when they heat up a little bit.
It does seem to stop pretty well, didn't do any empirical test like buckeye triumphs, but seems to stop better. I will see if I get used to the pedal being low, I would say instead of getting impending lockup at about 1/3 or pedal travel with the stock brakes it feels more like 2/3 travel with the upgrade, but they do pull it up sharply when applied, I have big tires (205/65) so having the big brakes to go with them seems to make sense. Will see if I get used to the new feel, and also if I can adjust a little more play out, but I think I may have done about all I can with it.
The presumably larger bore M/C conversion does intrigue me though, but I am just going to drive it a little, maybe I will get used to it. The do pull the car down from speed very well, I got semi-metallic pads, which always seem to get a little sharper bite when they heat up a little bit.
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OP
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I think I have success finally went for a long drive tonight and had good, consistent pedal the whole time. first problem was a boneheaded move I did when I put the right rear brake back together, second problem was a leak on the right front (seemed ok when I first bled the brakes, even held a white paper towel up to it after I bled and applied the brakes), which was solved by retightening the two flare fittings on the hard line out of the caliper.
Last problem, I think the new calipers were releasing the pads too far, when I fit the caliper initially their natural at rest state was separated from the disk, so tonight I did a couple things, I bent the release/anti squeal spring back a little so they didn't push the calipers out as much, and also gently pumped the brakes with the pads out to loosen and stretch the dust covers. Anyway the last bit seemed to do the trick, and now they are working well, I and I can feel an improvement in the braking.
Hope this may be of help to others who may go down this route.
Last problem, I think the new calipers were releasing the pads too far, when I fit the caliper initially their natural at rest state was separated from the disk, so tonight I did a couple things, I bent the release/anti squeal spring back a little so they didn't push the calipers out as much, and also gently pumped the brakes with the pads out to loosen and stretch the dust covers. Anyway the last bit seemed to do the trick, and now they are working well, I and I can feel an improvement in the braking.
Hope this may be of help to others who may go down this route.
OP
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There is more travel than I had before, but I would not call it disconcerting, by feel not any measurement the pedal feels like I am getting full bite, impending lockup at about halfway down, vs. a perceived 1/3 of the way before. I put on sem-metallic pads, which I had on my TR4a years ago. In both cases, they seem to lack good friction or bite unless they are warmed up. In fact your stopping power increases as they heat up, you can feel it in my opinion. I thought maybe with the booster on the 250 they would work better, thought wrong, still don't like them, have some Wagner ceramics on order.
I got one side off of Amazon, when they had a "loaded" caliper, including pads, for $30 something, too good a deal to pass up and inspired me to get started, unfortunately they only had one side, forget which, best deal I could get on the other side, was $53 or so with free shipping. Both are Raybestos rebuilt. Some parts search engines let you specify 4wd for your search, and some parts descriptions include that description as well, but not all, you do want the Toyota pickup calipers for the 4wd version, which has the 4 pot calipers, make sure you are getting that, I don't think Amazon has the deal anymore for the super low price.
I got one side off of Amazon, when they had a "loaded" caliper, including pads, for $30 something, too good a deal to pass up and inspired me to get started, unfortunately they only had one side, forget which, best deal I could get on the other side, was $53 or so with free shipping. Both are Raybestos rebuilt. Some parts search engines let you specify 4wd for your search, and some parts descriptions include that description as well, but not all, you do want the Toyota pickup calipers for the 4wd version, which has the 4 pot calipers, make sure you are getting that, I don't think Amazon has the deal anymore for the super low price.