Friday, May 12, 2006

I Bleedin Hope So

Since a damp and crash ridden ride around Cannock, last November, my Mono M4's have gone right off the boil. The levers now have loads a movement and if it weren't for the front working fairly well, I'd have had a miserable time around Coed-y-Brenin - tho I did find that riding without great brakes makes you commit !

To improve performance, I've tried cleaning the rotor's, changed the pads which makes 'em work ok for a time but in the wet their performance drops right off. I've even tried bleeding the rear, which is the worst offender and also the easiest to work on ;) but to no avail. Another set of new pads improved things slightly so a couple of sets must have gotten contaminated :x After the recent Ridge Ride, with very little modulation or power and after comparing Rob's rock solid lever "feel" to my soggy jobbies I decided that something else had to be done.

Whilst ordering a couple of rebuild kits from CRC I clocked Hope's own bleed kit which forces fluid through the system from a pressurised cannister unlike the ol'manual method of pumping the lever and topping up the master cylinder.

Hooking up the kit was straight forward, although the instructions could do with being clearer. Removing the wheel, pads, squeezing a spacer between the pistons and hooking up the pressure hose to the schraeder valve on my commuter (it only needs 20-25psi) had us ready to bleed. Unfortunately fluid pi$ed straight out of the master cylinder :rolleyes - not a good start. I traced the leak to a twisted seal so also I took the opportunity to wrench everything tight. Attempt#2 was much more successful as fluid was steadily driven out of the calliper, containing air bubbles too. A dozen or so steady squeezes with the lever and the bubbles had stopped. Interestingly, the fluid is driven through the system even without depressing the lever.

The lever now felt rock solid, especially with the max sized spacer holding back the pistons. Removing the kit, dowsing off the excess fluid, cleaning rotor and assembling bike I took her for a quick test ride but the alcohol needed fully burning off so a longer ride was needed. A good 18mile rip up the north side of MK had the solvent cleaned off, the pads biting nicely again and by this time I'd become accustomed to a much more solid lever feel, so it seems that we've cracked the problem :D

The front will be getting one of these bleeds shortly so I'll once again be able to dive deep into the corners before applying the anchors, hard :p The rear still isn't quite back to "as new" so I might install the lever and calliper repair kits as the seals could be a little tired.

I'm happy to report that Hope's Bleed kit works a treat and the new clear hoses make it much easier to see when the bubbles have stopped, compared to those on my ancient car bleedin botch job. Once you've got the hang of it, the process is quite quick although it's worth spending a little extra time to get it right first time *ahem*. The kit covers all Hope's braking systems as it comes with two different master cylinder caps for both the Hope Pro (open) and the old C2 (closed) levers.

9 Comments:


daahnhilla said...

SHIMANO SAINTS! YOU KNOW'S IT!;)


Farqui said...

Crikes, DDave is quiet and pressumed sleeping all wk before he wakes up "SHOUTING".

Tsk Sh!mano indeed - M4's rule boy-o, esp. now I've got the better of 'em.


daahnhilla said...

I've ran mine on the DH bike for two years, not needed a bleed or new pads yet, and they are more powerful...;)


Farqui said...

La-la-la, I can't hear you :p


daahnhilla said...

Carefull, I might wake up and start shouting again;):p


Dan Howell said...

These Hope things sound like a royal pain in the backside ;) far too much attention needed on them!

Open up a say "Haaaaayyyyeeeess" :)

...or Avid...

[cough]


Farqui said...

Sheeze, I now feel kinda guilty that I've highlighted this "SOLUTION" to the keyboard massif.

When they're working they're the best brakes I've ever ridden (and Rob too?) so perhaps it's down to my poor maintenance ? Go on you "tappers", diss me.

Shall the DDave & Brumster tag-team now be known as the "DH gansters" ?


daahnhilla said...

For the wet, I reccomend Sintered pads, and I'd take pads out, wheel off when you bleed, to avoid contamination, I've found dot fluid to be a particularly bad thing to get on your rotor or pads. I have some big bungs to shove in their place if you need.


Farqui said...

Yup, pads and rotor out when bleeding. Also have a can of brake cleaner handy to douse any spillages.

For bungs, I found some wood laying around that was just the right size to squeeze between the pistons. They'll also make handy spacers when transporting the bike with the wheel(s) out.

I tried sintered pads but suspect they got contaminated somehow 'cos they never provided any real bite. Resin pads give loads-a consistent bite and I'm happy to change 'em a little more often.

A pal who rides in Yorkshire says they get thru pads in a couple of rides :huh - regardless of bedding in or type of brake.


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