You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
From leaking Shimano calipers - and the front Hope has just randomly leaked 🤦♂️🤯
Had done 3 rides fine and it’s been sat on the turbo for a bit too. Then this morning I went to ride to work to a load of howling and lack of power from the front brake.
Had a look and there’s visible oil on the backing plates of the pads - looks like it’s just started leaking at random out of either where the connector is screwed into the caliper or the hose connector to the other connector. Odd
I’m going to pick up a new barb / olive and copper washers and start again I think.
In terms of pads and the rotor they were both new - and it’s a fancy expensive Xtr rotor.
What’s the best way to clean the rotor?
I’ve read elsewhere to sand the pads / heat the pads / blowtorch them / put them in the oven etc etc. Does any of that work?
Burning the pads off can work if the contamination is light. It can also lead to the back separating from the friction material. I have saved pads doing this however.
Rotor - Scrum with solvent / detergent and heat it up
Maybe I’ll give the lads a good clean and sand and a gentle heat and see if that saves them. They’re blue backed ones that came with the calipers - I’ve got a spare pair of red pads. I assume one lot are skntered and one lot resin or something like that.
Still really annoyed - can’t get my head round why it was working fine and then suddenly decided to leak. It’s definitely all tight etc - maybe the olive didn’t seat right or something - all the copper crush type washers are in correctly as far as I’m aware. Hate bleeding the Hope calipers with Shimano stis.
Washing-up liquid, and a toothbrush to clean the rotors,and a damn good scrubbing to get into all of the holes that hold the contamination, followed by a thorough rinsing under running water. I've lost count of how many times newbies in our workshop have ignored this advice, insisting that it'll be ok because they've sprayed it with brake cleaner, and contaminated another set of pads.
Going to be fun as they’re the rotors with the seperate aluminium cooling fins etc. Joy!
I had trouble getting my RX4+'s to seal at the olive. Kept tightening them until I was almost certain they were going to go pop. They leaked with a bit of oil on the pad backs. I also changed mine due to a leaky Shimano rear caliper since repaired with a very cheap eBay o ring and piston seal. <sigh>
I’ve had the rear a year or so and that one sealed fine on my old bike and this one. It’s the front that’s leaked - but the front seems to have a different setup to the rear. It has one piece that screws into the caliper with a large copper washer that looks to crush and seal. Then another shroud that screws onto that which has a small copper washer on a barb thing with an olive.
Need to have a better look at it and see if it’s leaking out the big copper washer bit or between that and the shroud. I’d say it’s done up VFT after an initial seep and had been fine for a few rides before leaking again.
I’ve ordered a new Barb / olive / shroud / both washers and the screw in bit to the caliper.
I have just wondered if the shroud / screw in bit I used maybe for 6mm braided hose rather than 5mm hose - there are spares in the box that came with the caliper so I wonder if they supplied both and I’ve used the wrong one without realising.
Made sure I’ve definitely ordered the stuff for 5mm regular hose so going to start from scratch with that and hope for the best. I’m the meantime I’ve removed the pads and rotor to clean them up ready to try again once the connections have all been changed. Might need to order some more mineral oil too thinking about it.
Sigh!
Both mine are like your front and I used 5mm Shimano hose. I even took it into the LBS to get them to look at it tho I've been doing all my own spannering since the dawn of time... Still some minor leaks and they started from the beginning front and back...
That doesn’t bode well 🫣
I've always just blow torched the pads till they stopped smoking and then cleaned the discs with solvent and a rag.
It can also lead to the back separating from the friction material.
Only had this happen once and it was from rust - my commuter, which lives outside 24/7, got a bit rusty....
[url= https://live.staticflickr.com/65535/51697829214_f563dfa91b_c.jp g" target="_blank">https://live.staticflickr.com/65535/51697829214_f563dfa91b_c.jp g"/> [/img][/url][url= https://flic.kr/p/2mLmTv1 ]Brake pad failure[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
Pretty sure my rx4’s look in better shape than those and will never live outdoors 🤣
They're 15 year old Magura Marta I think. Lockdown meant I stopped commuting, so it wasn't getting used and the pads weren't being heated up twice a day. Came to use once and found the front brake jammed on...
The friction material had been lifted off the backing by rust....
[url= https://live.staticflickr.com/65535/51697829209_3d4f4cc473_c.jp g" target="_blank">https://live.staticflickr.com/65535/51697829209_3d4f4cc473_c.jp g"/> [/img][/url][url= https://flic.kr/p/2mLmTuV ]Brake pad failure[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
Does any of that work?
Depends entirely on badly contaminated they are, if it's just a wee bit on the backing plate, then can't hurt to try, if the whole pad is wet with fluid, I'd bin them.
if the whole pad is wet with fluid, I’d bin them.
Blow torch till they stop smoking, any fluid will be long burnt off.
Keep us all informed of how you go / if the repair solves this.
I keep looking at sticking Rx4 calipers on my gravel bike (SRAM Force levers/shifters and calipers at present). Keen to avoid problems when I do bite the bullet and do it
Will update once the parts have arrived from sjs and I’ve got it all up and running again. Sounds like the rotor will be fine - have to see on the pads. Annoying if they aren’t recoverable as they were only 3 rides old or so.
My front caliper (new) has all 4 pistons moving nicely but the circa 1 year old rear (I think that’s how old it is) has one sides worth of pistons moving nicely and the other side not so much. When I bled it I tried to free them up but didn’t have a lot of luck. Think I need to get some silicone lube to get them moving better - although the brake is working pretty well regardless.
update here - I faffed about for ages cleaning rotors and pads and got everything working - but it seems like both calipers are leaking from the pistons in tiny amounts. I’m getting squealing and lack of power until the brakes warm up - when they’re a bit better. Just had both sets of pads out and both have moisture on the back.
This was why I went for Hope RX4 to avoid this as had it with a number of Shimano calipers micro leaking. Never had it with sram calipers - levels / guides / codes. It’s infuriating. Not sure what to do as I don’t want the bike off the road as I’m now commuting once a week on it - so don’t really want to send calipers off. One is in warranty but the other isn’t.
Even considering buying some Ultegra calipers at this moment in time…..
I thought my RX4 was leaking at the connector. Replaced the washer and olive, no difference. It turned out to be a hairline crack in the caliper body.
@ransos - that doesn’t sound good. Mine defo was leaking at the connector but I re did it with a new shroud / olive / Barb and it’s definitely not leaking there now (front). And yet I still have moisture on the back of the pads. Think I’m going to get cotton buds and ipa and give both pads and rotors a very thorough clean to make sure there isn’t just oil lurking about from bleeding before. Fit new pads I’ve already got (red ones). That takes all the variables away and if I then get moisture / oil then I know both calipers have a problem. At that point it’s both back to Hope for new seals and pads (one under warranty, one not).
Or I just pickup Ultegra ones and have done with it for a few years (until they micro leak).
If only I could have some flat mount Sram Code calipers with mineral oil seals and bleeding edge 🙏
Joe I’ve got a brand new front RX4 black. I ordered it incorrectly and never returned. Anyway, if you want it without pads, I could sell for £50.
@jkomo - thanks for the offer - that’s a good price. If it was a rear I think I’d take you up on it as having had another look this morning I reckon one or 2 of the piston seals are leaking. Cleaned it all up and going to test it tomorrow.
Having had a good look at the front I don’t think any piston seals are leaking so I’ve cleaned it up and fitted new pads. Again, will test tomorrow and see how it goes. The front caliper is new this year so should be in warranty.
No prob, good luck.
Hope are really good for support. When mine leaked, I sent them back and they installed all new seals. I don't think it was the seals (in hindsight), I think they were leaking from the hose union.
I have a suspicion the union is very sensitive to the hose spec. IIRC, Shimano comes (came?) in two slightly different outer diameters and 3rd party - who knows? If fitting again, I'd confirm what hoses Hope spec their joining hardware for and use that - only that. If it still leaks and you're sure the installation is good, I'd then get a refund.
I went to the trouble of eventually getting my RX4+'s reinstalled by my LBS. I've been installing hydraulic brakes for years and know what I'm doing (I think). I just wanted to exclude 'me' as a cause. There was still a small leak on the front. Afterwards it occurred to me I was running aftermarket hose.
'Shimano' compatible but exactly Shimano spec? Maybe...
@boblo - I’m on genuine Shimano hoses and the 5mm Hope hose hardware. Second time round it seems to have held on the front - never had a problem with the rear.
Hoping my front brake dramas are over now I’ve cleaned it all up / all the pistons move nicely / new pads in with a clean rotor.
It’s the rear that’s the issue. Got the 2 bore cap tools in my online shopping cart and the seal kit for the rear, but going to ring Hope for advice before clicking buy to see what they think. Don’t want to throw money at something if it isn’t going to fix it. Could pickup an Ultegra caliper for about £50 with new finned pads in it.
IIRC, Shimano comes (came?) in two slightly different outer diameters
2 different inner diameters. BH90 2.1mm and BH59 2.3mm. Both 5mm OD.
simondbarnesFull Member
IIRC, Shimano comes (came?) in two slightly different outer diameters
2 different inner diameters. BH90 2.1mm and BH59 2.3mm. Both 5mm OD.
Thanks. I couldn't recall the exact differences. I'd a memory of silver vs brass barbs but couldn't recall which/why. In which case my theory is probly absolute bolleux... 🙃
@joebristol Speak to Hope Tech Support (Johnny?) and he should help with the seals. He's an A1 character. 👍
Emailed Hope as their number wasn’t working. Now ordered the bore cap tools needed and the seal kit required. Going to have a crack myself - £8 per tool and just under a tenner for the seal kit. Vs Hope charge £34 plus p&p (without new pads) for a caliper refresh.
If I don’t cock it up it means less downtime with removing / posting the caliper etc.
Be aware that Hope were subject to a cyber-attack recently (hence the phone not working) and they are ploughing through a lengthy list of delayed orders. Please don't email the CEO if your bits don't arrive tomorrow.
No worries - I’ve ordered from shops who in theory are holding the stock themselves. SJS probably do have it - Biketart maybe quoting what their supplier has.
I wasn’t aware Hope had been attacked - I guess they don’t want to advertise that or they could have had a pop up on their website. Although I did get a capcha type thing just to go on their site so maybe they’ve put that there to try and increase security
So as long as nothing happens over the next few weeks to the front brake I think that is now sorted. Gave it a very thorough clean and fitted new (red) pads. Gave it 3 or 4 hard bedding in stops this morning and now it’s capable of throwing me over the bars from 30mph I reckon.
The rear is just howling with no power. Definitely leaking.
When you’re installing the hoses, are you doing it with the calliper attached to the bike? Is the cable internally routed? I’ve started removing the callipers to connect them to the hoses as the angles are often really tight and as it’s an aluminium calliper and a steel fitting, I don’t want to cross thread it or miss-shape the olive, which I’ve had happen more than once.
Both ends of my bike are internally routed and without a lot of free hose from the hose exit to the caliper. From memory I think the rear I attached before bolting the caliper to the frame but the front I loosely attached to the frame before connecting the hose.
Pretty sure both are now decently sealed with the olives and not leaking there. It’s the rear losing oil around the pistons on the outside of the caliper (bore cap side). I guess to change the seals I’m going to have to remove the rear caliper as it’s probably going to be a fiddly job. I’ve got a spare olive and Barb already sat on my work bench.
I’ve rebuilt hubs / forks etc and built wheels - but I’ve never tried removing seals and pistons from a brake caliper before so this is new to me. Hope it goes ok!
I resealed the pistons and the transfer ports in my Shimano calipers recently. It was simple and very obvious. Assuming you're not a mechanical dunce (no disrespect intended), you should be fine. Though, perhaps give it to a 'friend' to test on the nearest steep hill... 😁
@boblo - hopefully I’m not a dunce when it comes to bike maintenance but my last effort at bleeding the front brake but with the bleed funnel on the rear brake lever may suggest otherwise 🤣
my last effort at bleeding the front brake but with the bleed funnel on the rear brake lever may suggest otherwise 🤣
Bet that took some time... 🙃
Thread resurrection!
Just bought a new RX4 rear for the winter bike I’m building. I bled it last week and have been away on holiday. Came back today to centre it and fit pads but spotted a bit of fluid in the caliper. A quick clean then a squeeze with the bleed blocks in place gave me this:
Assume it’s just back to hope for a new set unless there’s something magic I can do to stop them leaking? Quite annoyed cos I keep getting bits delayed in this bike. It’s been ‘just a couple of wee bits away’ for weeks now!
It can also lead to the back separating from the friction material.
ONLY if there is some sort of shock cooling involved, and TBH i've been hearing about this supposed/alleged separation since about 1996, and I've yet to see or have it happen.
Consider how hot those pads are going to get in a long alpine use.I would think 160c wouldn't be far off*.
Is that going to be more than running a blowlamp flame over them to burn off contamination. Hold the blowlamp on it till the backing pad is cherry red it probably going to cause issues, but thats never what you'll be doing
.
* Obviously rotor size is going to play a part along with how big a mincer you are.
Consider how hot those pads are going to get in a long alpine use.I would think 160c wouldn’t be far off*.
A lot hotter than that! I have had this happen after heating pads that the friction material came away
@stevious - is that brake fluid just loose on the caliper? I found 2 of the pistons looked let on the edges of them that touch the seals when you pumped them out a bit against the bleed blocks - the other 2 looked dry. I replaced the seals on the 2 wet ones and so far so good - the brake isn’t leaking / squealing / howling now. I’m struggling a bit to get a firm enough lever on the rear - I must still have air somewhere. I’ve followed the full instructions but going to have another go when I get a chance.
The front one has a very firm lever and bags of power but rubs noisily on the disc sometimes. I think that one needs the pistons resetting and the caliper realigning. But between them they have more than enough power so I’m just riding it as it is at the moment.
I’ve found the red pads aren’t as good in the wet as the blue ones - you need to burn the water off with a few big brake applications to get their power back after a few miles of riding in the rain / puddles. The blue ones don’t need this.
Just updating this - I’m done with the RX4s. They’re pretty, but finding them unreliable.
Having rebuilt one of the calipers and having stopped the leak from the olive joint bit on the other my brakes were ok. The front was powerful enough it felt like hitting a wall and was really pleased with it. The rear not so much - was struggling to get all the air out so had a soft lever. Still - it was fine.
Had a couple of months out with appendicitis and recovery - commuted on the bike recently and they’ve gone to s*** again. Both howling and lacking in power.
Given up and bought a pair of Ultegra flat mount calipers to replace them. Did consider trying Magura MT8 flat mounts but reading online I’d have need to change the brake hoses to Magura ones and I cba with the internal routing and retaping the bars.
Will be banging the RX4+ calipers on eBay when I get a chance with a suitable health warning about them being finicky and see what I can get back to offset the Ultegra caliper costs.
I've had a front caliper for about 18months that i've been undecided about fitting, and the tales on here have helped me decide to sell them on! They do look great, and would look neater than the post-to-flat adapter I currently use. But then again, the cheap deore calipers i've used have been faultless and work well. If I get flat mount calipers they'll be shimano.