[Orvan]

What a crappy friday night.. The usual way I vent out my frustration is to work on my bike (for no apparent reason) or bike parts. Tonight's victim is my 1999 Hope DH4 Master Cylinder.

The routine removal and installation involved in these procedures practically apply to all Hope brake system (I own/owned almost all models).

This crappy evening's topic is brought to you by the cool new Nicolai Nucleon World Cup...Radical Dude

HOPE DH4 MASTER CYLINDER SEAL KIT/PLUNGER REPLACEMENT AND REBUILD

 

[Orvan]

What would you need to have (granting you own and are working on a Hope system)

Uhmm..the Master Cylinder/Lever assembly is a good start
2mm Allen Hex Key
2.5mm Allen Hex Key
3mm Allen Hex Key
4mm Allen Hex Key
Cleaning brush (I'm just a neat freak)
Small long needle nose plier
8mm open end wrench
C-Clip Plier -one with yellow grips (with small enough pins for the hope C-clip holes) - this is the most important tool to have for a fuzz free operation. Sears sells them for cheap....get the craftsman as it offers a variety of pins and is adjustable..for only $8.

Paper towel too...

 

[Orvan]

The replacement parts.
If you don't have the seal kit which includes the plunger with new seals, brass washer, ball plunger, c-clip and dust cover, then it's pointless for you to even proceed rebuilding it... Make sure to atleast have the plunger or the upper and lower seals for the plunger and the brass nut. Call Hope Technology (Gwen and Bill) for pricing.

There is a change in the plunger design.
If you observe the top plunger (for the old DH4s), the upper (facing away from the spring) seal is smaller while the one below it (upgraded plunger-retrofit) is wider and bigger. The old (smaller seal) ones tend to develop leak over a shorter period of time compared to the new design.

 

[Orvan]

Next... Lever disassembly.
While holding the 8mm nut at the bottom of the lever pivot point with an 8mm open end wrench, use the 3mm allen hex key (Note: Some Hope system use 4mm hex head instrad of 3mm) to back the lever pivot bolt out.

Tech Tip: Hope owners, when your lever feels rattly/up and down slop (and obviously makes rattling sounds while riding), it's an indication that the 8mm nut on the pivot point has loosed up. Simply tighten it (preloading the bushing). You will need to find that sweet spot where it's tight enough but not binding the lever motion. The lever feel will improve beautifully if you pay attention to this small detail.

 

[Orvan]

After the 8mm nut is removed and the pivot bolt pulled out, the lever is now held my the ball plunger arm to the master cylinder. Observe the sequence of the little parts when you disassemble them so you know how to put them back for re-installation.
Note the two plastic bushings (one sitting on top of the lever, one away and on the paper towel), make sure they're clean when reinstalling.

Tech Tip: Hope Owners, when your brake is making squeaking noise at the lever area, the bushing is the culprit.. Simply spray the pivot point area with WD-40 and viola.

 

[Orvan]

To remove the lever blade from the plunger assembly, use the 2mm allen hex key to loosen the set screw atop the brass bango which the ball plunger arm is threaded into.

Once the set screw is way loose, use the 2.5mm allen hex key at the end of the ball plunger arm (front of the lever part) and thread it clockwise all the way. This process will back the ball plunger out of the brass bango to detach the lever from the master cylinder.

 

[Orvan]

Once the lever is removed.. Take the rubber dust boot out and you will see the outer plunger assembly (C-clip over the brass nut).. This is a good time to use the cleaning brush to clean this area of foreign debris to avoid contaminating the master cylinder housing during removal.

 

[Orvan]

Using the C Clip Plier, place pins on holes and squeeze the c clip arms together and pull it out. The brass washer should follow suit along with the ball plunger.

 

[Orvan]

Once the C-clip/brass washer/Ball Plunger assembly is removed, the plunger (with seals) will be exposed. Using the small long needle nose plier, firmly grasp the plunger head on the edge and pull (make sure you're doing this procedure over a rag or somewhere or over something the brake fluid can run or drip onto).

 

[Orvan]

Pull out the plunger. Discard the old seals (new upper and lower seals can be order thruough hope for future use of the plunger).
At this point, you can drain the remnants of the brake fluid and clean the outer area of the cavity from foreign stuff.

 

[Orvan]

Installation the new plunger..

The updated plunger with the bigger upper seal is not that easy to wedge back in. Due to the bigger seal size, the tolerance has gotten tighter. To prevent marring (and ruining) the new seal, assist the plunger as you push it back in the master cylinder with a small pointy thingie (I use a real tiny sewing needle like thingie) to work the edges of the upper seal into the master cylinder.

uh oh...the effect of the beer is waning...I'm getting sober...why am I doing this techie demo crap????

 

[Orvan]

Just in case you've forgoten, this is the sequence of the ball plunger assembly as you would re-install it.. C clip over the brass washer thru the ball plunger arm..

 

[Orvan]

Again, it's always good to replace the old brass washer with a new one (this is the break away feature of the Hope levers).
Using the C-clip plier, squeeze the c-clip and reinstall the ball plunger assembly back.
Note: There is a groove where the C-clip needs to be seated... Inspect the master cylinder outer cavity rim early in the removal process so you know where it's at roughly.

Tech tip: It will be easier to reinstall the c-clip over the brass washer if you push down on the plunger as you seat the c-clip.

From here, reassemble everything by just reversing the lever disassembly procedures....cuz I'm sure as hell sober now and about ready to get some Zzzzzzzs..

Does this help to all Hope owners??

Oz:

 

[Brian HCM#1]

Still no job hunh? Actually really helpful pics and discriptions for the rookie Hope person. Good job

 

[Orvan]

Originally posted by Brian HCM#1
Still no job hunh? Actually really helpful pics and discriptions for the rookie Hope person. Good job

yup..still on dole.. Jared is fired so Subway is looking for a new geek for their commercial but I'm such a punk to be casted on that..

Now if only someone could post a detailed pic and description series on how to service rolhoff hubs... :devil:

 

[LOOnatic]

Outstanding Do-it-yourself article Orven.
New job should be doing this type of informative tech stuff and analysis\review for lets see,.........a website naturally.
Hmmm, if i could just think of one?????

Oh, and uh, when's the Hayes article coming?

 

[Orvan]

Originally posted by LOOnatic

Oh, and uh, when's the Hayes article coming?

as soon as the brake fluid dries up in my frustration trash bin, I'll post it..you should post it since you spent the most time on Hayes than I have
:devil:

 

[oldfart]

Good stuff Orven. really good stuff. If you're looking for work, you should call up Hayes and offer to put together an instruction manual which can be followed easily. Hayes' book is awful with all those warnings every second sentence. And that hand looks suspisciously clean. You're not the anal retentive mechanic are you. ??? Oh my, I've soiled this hand, I'll just clean that off now....

 

[Brian HCM#1]

Originally posted by oldfart
Good stuff Orven. really good stuff. If you're looking for work, you should call up Hayes and offer to put together an instruction manual which can be followed easily. Hayes' book is awful with all those warnings every second sentence. And that hand looks suspisciously clean. You're not the anal retentive mechanic are you. ??? Oh my, I've soiled this hand, I'll just clean that off now....

Yeah thats a good idea!!!!! Orven I'll help.

1) Remove Hayes lever and caliper and any adapters.
2) Remove brake line from frame & fork.
3) Toss in nearest trash bin.
4) Open the box to your new Hope brakes.
5) Install
6) Enjoy the best brakes ever.

I think the directions needs a little tweeking, but its a start.

 

[LOOnatic]

Originally posted by Brian HCM#1
Yeah thats a good idea!!!!! Orven I'll help.

1) Remove Hayes lever and caliper and any adapters.
2) Remove brake line from frame & fork.
3) Toss in nearest trash bin.
4) Open the box to your new Hope brakes.
5) Install
6) Enjoy the best brakes ever.

I think the directions needs a little tweeking, but its a start.

Ha Ha Ha Ha Brian,

I have learned this the hard way and know totally agree..
M4's here i come. With Hope, is the 205mm=8", or the 185mm?

 

[Brian HCM#1]

Originally posted by LOOnatic



Ha Ha Ha Ha Brian,

I have learned this the hard way and know totally agree..
M4's here i come. With Hope, is the 205mm=8", or the 185mm?

205 is the 8" for the front for a IS mount you will need a #8 caliper. For a Boxxer you will want the #6 205 caliper. The reg #6 is for a 185 rotor. A #8 caliper for the rear will be a 185 rotor. If you want to run 8's all around you'll need a 20mm adaptor with a #8 caliper for the rear. However the 185 works fine. The standard #3 caliper's F&R would be a 185 front & a 165 for the rear. Hope this helps.

 

[Brian HCM#1]

Originally posted by Acadian
That is just awesome Orver...actually I had to do a bleed job on my hopes yesterday.

so tell me about that plunger assembly! I still have the same levers that originally came with the DH04's and never changed those, although I have changed many of those brass washers...do you suggest I order new plungers as they seal better?

I would change them only if its leaking. Slice crashed his bike last year and F'ed up the washer and started leaking there, so I replace the washer and it still leaked. At that point I had to rebuild the lever assembly because there was damage to the seals from his crash.