troubles with a TRP Hy/Rd disc caliper

cooperplace

I've got one of these that I use on the front of my road bike, on a 180mm disc so it should be really powerful. I got it a couple of years ago but I've never got it to work properly. When I first installed it, I found that I could only get an acceptable lack of lever free play by adjusting the slack with a cable adjuster, which I did.

By the way, there was nothing in the instructions to say that this was wrong. Of course this stopped the actuating lever from fully returning to its correct position and eventually the unit got air in it.

I took it off and bled it, and bled it, and bled it. I've bled it on the bike, and off the bike. I've pushed about 250mls of mineral oil thru it, and still I can't get an acceptable lack of lever free play. There is plenty of meat left on the pads. It's as if the automatic pad wear adjustment isn't working.

I've now removed it from the bike and I'm using an Avid BB7 which works MUCH BETTER, which it shouldn't.

On the plus side, it's much easier to align than the BB7, which is a pain. But the lever comes in to the handlebars.

Does anyone know how I can get the Hy/Rd to work properly?

ugo.santalucia

you might have a faulty one... there are a few around.
I suggest you write an email to TRP explaining your issues. I did the same, they came back to me rapidly and offered to replace the unit, even if it was no longer covered by warranty. The all process was painless, the UK distributor sent me a new one and then I returned the faulty one.
The new one never skipped a beat

cooperplace

ugo.santalucia wrote:

you might have a faulty one... there are a few around.
I suggest you write an email to TRP explaining your issues. I did the same, they came back to me rapidly and offered to replace the unit, even if it was no longer covered by warranty. The all process was painless, the UK distributor sent me a new one and then I returned the faulty one.
The new one never skipped a beat

good thinking, and it's great to hear that TRP stand behind their product. I've emailed them; will let you know what happens. Personally I think it must be faulty.

ugo.santalucia

cooperplace wrote:

ugo.santalucia wrote:

you might have a faulty one... there are a few around.
I suggest you write an email to TRP explaining your issues. I did the same, they came back to me rapidly and offered to replace the unit, even if it was no longer covered by warranty. The all process was painless, the UK distributor sent me a new one and then I returned the faulty one.
The new one never skipped a beat

good thinking, and it's great to hear that TRP stand behind their product. I've emailed them; will let you know what happens. Personally I think it must be faulty.

I had similar problems, mine did not compensate for wear, despite me not using the screw... let me down on a couple of occasions, so eventually had to contact TRP... very useful, no nonsense people

tsarouxaz

on the side of the hyrd, right under the reservoir, does it say "mineral oil" anywhere? the new improoved ones do say that. if you have the old ones, then you should contact trp for a replacement. the new ones are VERY good, a lot closer to full hydraulic that enything else. ( I have tried a lot of mechanical disk calipers believe me...)

cooperplace

cooperplace wrote:

ugo.santalucia wrote:

you might have a faulty one... there are a few around.
I suggest you write an email to TRP explaining your issues. I did the same, they came back to me rapidly and offered to replace the unit, even if it was no longer covered by warranty. The all process was painless, the UK distributor sent me a new one and then I returned the faulty one.
The new one never skipped a beat

good thinking, and it's great to hear that TRP stand behind their product. I've emailed them; will let you know what happens. Personally I think it must be faulty.

Well, I've had a lot of contact now with TRP and I haven't found them very helpful. I've bled it lots of times and fianlly got all the air out by using long flexible bleed tubes so I could tip the unit over while bleeding. The short stiff bleed tubes in the TRP kit are not ideal. Replacing the pads made a huge difference, even tho' they had 1.4mm left and had never seen any contamination. But now it's dragging, and I can't get this to go away even with re-aligning it. It's had enough use to break in the pads. Any suggestions re how to fix this would be appreciated.

meanredspider

cooperplace wrote:

Well, I've had a lot of contact now with TRP and I haven't found them very helpful. I've bled it lots of times and fianlly got all the air out by using long flexible bleed tubes so I could tip the unit over while bleeding. The short stiff bleed tubes in the TRP kit are not ideal. Replacing the pads made a huge difference, even tho' they had 1.4mm left and had never seen any contamination. But now it's dragging, and I can't get this to go away even with re-aligning it. It's had enough use to break in the pads. Any suggestions re how to fix this would be appreciated.

Im intrigued by all of this bleeding you are doing. There's no hydraulic lines so you're just getting air out of the unit itself?

I'm also concerned by your comment that "it's had enough use to break in the pads" - you don't do the break-in procedure by just riding - it's a proper effort to brake hard enough times sequentially to get the disc really hot.

I do wonder at this point if you should be getting some practical help from an LBS or somebody. Apart from a faulty original calliper that didn't self-compensate, I've fitted my HyRd and not touched it except for occasional pad changes. It's been great and infinitely better than the BB7.

cooperplace

meanredspider wrote:

cooperplace wrote:

Well, I've had a lot of contact now with TRP and I haven't found them very helpful. I've bled it lots of times and fianlly got all the air out by using long flexible bleed tubes so I could tip the unit over while bleeding. The short stiff bleed tubes in the TRP kit are not ideal. Replacing the pads made a huge difference, even tho' they had 1.4mm left and had never seen any contamination. But now it's dragging, and I can't get this to go away even with re-aligning it. It's had enough use to break in the pads. Any suggestions re how to fix this would be appreciated.

Im intrigued by all of this bleeding you are doing. There's no hydraulic lines so you're just getting air out of the unit itself?

I'm also concerned by your comment that "it's had enough use to break in the pads" - you don't do the break-in procedure by just riding - it's a proper effort to brake hard enough times sequentially to get the disc really hot.

I do wonder at this point if you should be getting some practical help from an LBS or somebody. Apart from a faulty original calliper that didn't self-compensate, I've fitted my HyRd and not touched it except for occasional pad changes. It's been great and infinitely better than the BB7.

of course I'm just getting air out of the unit itself: as you say, there are no lines. Clearly the bleed fittings attach to tubing.

"it's had enough use to break in the pads" yes, i can read the instructions. Like I say, it's had enough.

Advice from a LBS: are you kidding? Do you know what sort of people run these places? What do you take me for? I'm all for supporting local businesses, with the definite exception of LBSs. I've seen how useless they usually are.

I'm glad that your Hy/Rd is better than your BB7. My experience differs from this. As mentioned above, I've had extensive communication with TRP about this and haven't found them helpful.

If you have some knowledge that's useful and relevant to the Hy/Rd, I'm happy to hear it.

veronese68

I don't know what instructions they give, but as MRS said, normal braking is not enough to bed in the pads. To properly get them bedded in you need to get up to speed and brake hard, but not quite to a standstill. Then get back up to speed and again brake hard but not to a standstill and keep repeating until you get a decent brake. I think it takes about 10-12 cycles before it really takes effect. Normal braking can actually make my rear brake worse as it isn't used as hard as the front, I have to make a conscious effort to use it harder than normal every now and then to stop it glazing.
With regards to the dragging I take it you've released the cable tension you mention adding in the first post. Does it still drag with the cable disconnected? If so you may have pressurised the unit slightly when bleeding it. Crack a bleed nipple open to release a bit of the pressure.

cooperplace

Veronese68 wrote:

I don't know what instructions they give, but as MRS said, normal braking is not enough to bed in the pads. To properly get them bedded in you need to get up to speed and brake hard, but not quite to a standstill. Then get back up to speed and again brake hard but not to a standstill and keep repeating until you get a decent brake. I think it takes about 10-12 cycles before it really takes effect. Normal braking can actually make my rear brake worse as it isn't used as hard as the front, I have to make a conscious effort to use it harder than normal every now and then to stop it glazing.
With regards to the dragging I take it you've released the cable tension you mention adding in the first post. Does it still drag with the cable disconnected? If so you may have pressurised the unit slightly when bleeding it. Crack a bleed nipple open to release a bit of the pressure.

thank you for the detailed advice re how to break in pads. As noted above, I'm aware of this. Yes, it still drags with no cable tension. I hadn't tried cracking a bleed nipple, because "pressurizing the unit while bleeding" is unlikely. Nonetheless, cracking a bleed nipple hasn't fixed it.

veronese68

Apologies, I missed the part where you said you'd followed a bedding in procedure. As I said I don't know what the instructions say, the only information you gave was that you'd ridden it enough to bed them in and had followed the instructions. I thought a bit of clarity may help, but obviously not.
Hope you get it sorted, most people seem to like them.

cooperplace

does anyone have any experience taking these things apart? I'd like to clean out the inside and check that there isn't any crud blocking the pistons. I can't find anything online describing overhaul of these.

ugo.santalucia

Could it be dragging because the disc is warped? WIth 180 mm rotors it is very common

meanredspider

Well I didn't think you originally described the of breaking in the pads very clearly - use has nothing to do with it and actually makes things worse if the original procedure isn't done. But we now understand that it's done properly.

Do you have any idea how you got air into the system in the first place?

Are both pads dragging or just one? Can you press both pistons back? Without pads (and being careful not to drive the pads out completely) applying the brakes and releasing should see the pistons extend a lot on the pressure stroke and retract slightly on release. It's worth checking that they're retracting that small bit.

If there's loose dirt in the system, the pressure bleeding procedure (with the syringe) should wash through any dirt with the air. Personally I avoid breaking into any hydraulic braking system if I can help (or have good reason to do it) it as you're likely to introduce more problems than you solve - but you've crossed that bridge. I guess that you followed the video

https://youtu.be/FFgrHBrO_00

Are the pads free to move properly? Caliper lever and cable moving freely?

After all that, that's all I can think of. There aren't many people that have had HyRd problems other than the original fault.

cooperplace

ugo.santalucia wrote:

Could it be dragging because the disc is warped? WIth 180 mm rotors it is very common

I don't think so. I've tried several discs. There's no pulsation during braking that you might expect from a warped disc.

cooperplace

meanredspider wrote:

Well I didn't think you originally described the of breaking in the pads very clearly - use has nothing to do with it and actually makes things worse if the original procedure isn't done. But we now understand that it's done properly.

Do you have any idea how you got air into the system in the first place?

Are both pads dragging or just one? Can you press both pistons back? Without pads (and being careful not to drive the pads out completely) applying the brakes and releasing should see the pistons extend a lot on the pressure stroke and retract slightly on release. It's worth checking that they're retracting that small bit.

If there's loose dirt in the system, the pressure bleeding procedure (with the syringe) should wash through any dirt with the air. Personally I avoid breaking into any hydraulic braking system if I can help (or have good reason to do it) it as you're likely to introduce more problems than you solve - but you've crossed that bridge. I guess that you followed the video

https://youtu.be/FFgrHBrO_00

Are the pads free to move properly? Caliper lever and cable moving freely?

After all that, that's all I can think of. There aren't many people that have had HyRd problems other than the original fault.

Thank you for the excellent list of diagnostic tests. I think air got in because, prior to implementing the actuation arm modification recommended by TRP and described here:

https://www.youtube.com/watch?v=8aBa3sGUUhs

I had used an inline cable adjuster to improve the lever feel. I think this prevented the actuation arm from returning to its home position, and I'm told this eventually lets air in. The actuation arm certainly returns to its correct position now.

With the wheel and disc removed, on squeezing the lever, both pads move in equally, nicely, and on releasing the lever, both pads move out equally. There's no:
"should see the pistons extend a lot on the pressure stroke and retract slightly on release"

instead they move an equal amount on in and out strokes.

The brake lever, cable and actuation arm (is that what you mean by caliper lever?) all move freely.

The dragging seems to be evenly all around a revolution of the wheel/disc. There's no evidence of a warped rotor.

Re bleeding, I've bled it about 10 times and I've watched that video. The TRP people sent me the link. I think my procedure is better: I use long (ca. 500mm) flexible plastic tubing which lets me rotate and tilt the caliper while applying pressure on the syringe so as to get that last bit of air out. All the brake fluid comes out looking nice and clean.

I don't think there's much air left in it.

I know that many people have excellent experience with the Hy/Rd, but the relevant point is that not everyone is 100% happy with it.

I also have a MTB with Tektro all-hydraulic discs, for comparison, and these don't drag at all. And work a lot better.

If anyone has experience taking these apart, I'd be happy to hear of it.

I can to some extent live with the dragging: I just get a better workout, and the disc gets a bit warm. But I'd like to fix it.

meanredspider

I'm a bit surprised that TRP recommend that modification - there can't be many companies that support you taking a hacksaw to a brake. I wonder what that does to the effort you need to apply to the brake and I suppose this might be why you prefer the BB7.

I'm wondering if somehow, with your in-line adjuster originally fitted, you damaged the brake. If air got in, it had to get in somewhere that it wasn't designed to either because you drew a vacuum somehow within the caliper or because fluid escaped. Either way, it's likely some form of seal failed - possibly in the piston.

Does the brake rub evenly on both faces of the disc or is it just one pad? I'm assuming it's both faces else you should be able to realign the caliper. If the pistons retract as you say, then I can only imagine it's the pad itself sticking. Certainly, I wouldn't ride with a rubbing pad. You'll glaze the pad (or pads) and make them useless - not to mention any other heat-related effects like warping the disc or boiling the fluid. If it isn't working properly, I'd take it off.

I actually only run one HyRd (on the front of my Volagi) and a BB7 on the back - mostly because I do 95% of my braking using the front only. It was actually pretty useful because I was using one of the original (faulty compensation) HyRd calipers when descending Alpe D'Huez a few times and the front would run out of adjustment but I could at least rely on the rear BB7 to share the load.

Good luck with solving it but I'd be tempted just to replace the thing. If it's not working right you could reach a point where it fails catastrophically.

svetty

cooperplace wrote:

......
With the wheel and disc removed, on squeezing the lever, both pads move in equally, nicely, and on releasing the lever, both pads move out equally. There's no:
"should see the pistons extend a lot on the pressure stroke and retract slightly on release"

instead they move an equal amount on in and out strokes.

The brake lever, cable and actuation arm (is that what you mean by caliper lever?) all move freely.........

If the pads are moving freely in and out again I don't see what the problem is. If the pads are moving back out after braking how are they dragging??

timothyw

Presumably the brakes are dragging on one side of the rotor - might it just be a case of re-centring the caliper?

So loosen the bolts that hold the caliper until it is free to move side to side, then apply the brake, then while holding the brake lever tighten the caliper bolts?

svetty

TimothyW wrote:

Presumably the brakes are dragging on one side of the rotor - might it just be a case of re-centring the caliper?

So loosen the bolts that hold the caliper until it is free to move side to side, then apply the brake, then while holding the brake lever tighten the caliper bolts?

If he's done all that he has including bleeding I suspect this will have been tried......

cooperplace

meanredspider wrote:

I'm a bit surprised that TRP recommend that modification - there can't be many companies that support you taking a hacksaw to a brake. I wonder what that does to the effort you need to apply to the brake and I suppose this might be why you prefer the BB7.

I'm wondering if somehow, with your in-line adjuster originally fitted, you damaged the brake.

Does the brake rub evenly on both faces of the disc or is it just one pad? I'm assuming it's both faces else you should be able to realign the caliper.

Good luck with solving it but I'd be tempted just to replace the thing. If it's not working right you could reach a point where it fails catastrophically.

yeah, I was amazed that they recommended this; it would never happen in aviation for example.

I don't see how letting in air would damage the Hy/Rd.

I can't tell which pad is dragging but attempts to re-align it don't work.

The pads seem to retract freely but not far enough: that's the key to the problem. Further to this, when I'm fitting new pads, I push the pistons back, as required, but they then slowly push forward. One thing I haven't tried is cracking a bleed fitting while pushing the pistons back because that seems like a sure way of letting air in, and I don't want to bleed with pads in because they get contaminated.

There's no possibility, as far as I can tell, that this fault will lead to a catastrophic failure.

Yes I will probably just end up replacing it.

I've asked TRP for overhaul instructions several times but they haven't provided these. If I buy another one I'll take this one apart.

cycleclinic

I had issues with my hyrd's got rid of them and fitted spyres. Upgrade tried blaming my installing hmmm I dont think so. What happened was different after a year of use the pistons went a bit skewiff (I still dont understand how) and the pads dragged.

cooperplace

I'll probably end up replacing this. To get an idea of how much it drags, with the bike up on the stand, if I spin the front wheel fat it stops after about 1.5-2 turns. The rear wheel (which has a ratcheting freewheel: energy losses?) turns maybe 30-40 revolutions, it goes on forever.

This dragging translates into the disc getting warm without brake use. I just did a big descent and stopped with rear brake only. The temperature of the front disc was I guess 40-45C, so warm not hot. Ambient was about 32C.

So apart from the annoyance, the concern is that it will glaze the pads. It hasn't yet however, as braking effort remains very good.

BTW, the hacksaw modification to the actuation arm causes a slight but not unacceptable increase in required lever force.

cooperplace

TRP recommended doing a piston exercise to help lubricate the seals and to
clean out any dirt trapped between the caliper body and piston:

"1. Start by removing the pads
2. Use a tire lever, or box-end wrench, or something to hold the
freely-moving piston in place
3. Actuate the brake to get the sticking piston to move out slightly - no
more than 3mm, as you don't want it to pop all of the way out.
4. Use a Q-tip and mineral oil to clean around the piston. The mineral oil
will also act as a lubricant.
5. Use the tire lever/box-end wrench/etc. to push the piston back in.
6. Hold the other piston in again while actuating the brakes to push the
sticky one back out.
7. Repeat 5 & 6 a couple of times. Do the same with the other piston, so
they're both starting over clean and lubed"

This made no difference at all.

6wheels

Why they can't put bleed nipples on I'll never know, anyway...

The pads seem to retract freely but not far enough: that's the key to the problem. Further to this, when I'm fitting new pads, I push the pistons back, as required, but they then slowly push forward. One thing I haven't tried is cracking a bleed fitting while pushing the pistons back because that seems like a sure way of letting air in, and I don't want to bleed with pads in because they get contaminated.

Cracking the bleed fitting seems worth a try, just cut a piece of wood the right size to replace the pads.

cooperplace

i just heard back from TRP. They think, based on its behaviour without pads in it (i.e. no amount of lever pressure pushes the pads very far) that it still has air in it.

I'll try bleeding it again.

cooperplace

I've bled it some more, and not 1 bubble came out. TRP think there is till air in it so I'm sending it to them.

I've fitted the BB7 now and on doing my favorite ride, easily shaved a few minutes off my PB, so I think I've been underestimating the difference this dragging was making.