OzVMX Forum

Marque Remarks => Honda => Topic started by: Photomike666 on May 28, 2015, 09:42:49 pm

Title: 87 CR250 front brake
Post by: Photomike666 on May 28, 2015, 09:42:49 pm
I'm at the start of a Resto project, and am lucky enough that the bike I purchased runs good enough for a good fang around the local track.

One of the major problems I'm finding if the lack of feel and stopping power from the front brake.  I know the bike has been parked for 6 years and the pads are glazed over, but despite having heaps of pressure at the lever it's really wooden and lacks any bite.  The rear pulls the bike up far better from speed.  It's 20 odd years since I rode MX bikes of this era, and I've been spoiled by modern era sports bikes.  Questions is, is this normal or just a stuffed brake?

I'm thinking of changing the caliper anyway as the stock unit has had a bolt stripped and redrilled, but do I go stock or is there something better out there that will fit an 87 CR250?  I guess I don't want to replace / rebuild the whole system only to find they're "just like that" and I should have taken a different option from the start.

All advice greatly appreciated.
Title: Re: 87 CR250 front brake
Post by: smed on May 29, 2015, 06:05:32 pm
The brake should work reasonably well, Is the disc ok? Not bent or badly worn where the pad contacts,A new set of pads will work wonders if the old pads are glazed or oil contaminated, Organic pads will give much more bite than sintered pads but will not last as long, If you go down the swap out route I think up to 92 model parts or perhaps even later will fit but am not 100% sure,you would need to do a few measurements :)
Title: Re: 87 CR250 front brake
Post by: Momus on May 29, 2015, 06:43:12 pm
Ghetto brake refresh:

If there is meat on the pads and they are not oil soaked,  linish the top half a mm from them and give the disc a good scour with 120 or so wet and dry, then a clean with thinners or prepsol.

Should be a marked improvement.
Title: Re: 87 CR250 front brake
Post by: Nathan S on May 29, 2015, 07:19:38 pm
An 87 CR brake is exceptional for 1987, and still alright by modern dirt bike standards.

Do what Momus said, and report back.
Title: Re: 87 CR250 front brake
Post by: Slakewell on May 29, 2015, 08:02:51 pm
You wonder why 30 year brake fluid is shit and the pads are clazed?
You dont think as a hydrospoic fluid it dosent have some water after all this time?
One mornings work should fix your problems.
I would anti seize the pistons in clapitor as well 
Title: Re: 87 CR250 front brake
Post by: sa63 on May 30, 2015, 05:25:03 am
Ihave one set (88) which is 1 finger vicious,yet another set(89), bled a few times, new pads (swapped pads even)etc, are wooden ...been meaning to pull them down to find out what the problem is...
But if you jump from a drum brake bike to disc, wooden is an easier transition...
Title: Re: 87 CR250 front brake
Post by: Slakewell on May 30, 2015, 05:12:17 pm
Check youtube for tips there is just about everything these days.

https://www.youtube.com/watch?v=zFOa1yY6WGI
Title: Re: 87 CR250 front brake
Post by: mr500 on June 24, 2015, 10:31:15 pm
Mate the caliper pistons are 'seized' that's why the lever is hard but the brakes are crap.Seen it heaps.

Why? because when a bikes sits around the brake fluid turns to mud and crap gets behind the seals pressing then against the pistons and making them tight, they aren't really seized, just uber tight.
Cure ? Easy just get a new caliper seal kit, they are really cheap and as far as I know they fit Honda CR's 125/250/500  from '84 to '01 or later- same seals.

You don't even have to remove the brake hose, use the lever to pump out the pistons-clean the caliper (spotless) fit new seals, (lube seals after words) install clean pistons.
Hold the caliper above the master cylinder to let the air go up, put something like a block of wood between the pistons and caliper body, bleed in that position.
Refit the caliper and ride.  8)

My just finished '87 CR500 resto.

(http://i115.photobucket.com/albums/n309/gtr_05/crfin2_zpswbd8j4bi.jpg) (http://s115.photobucket.com/user/gtr_05/media/crfin2_zpswbd8j4bi.jpg.html)
Title: Re: 87 CR250 front brake
Post by: Brian Watson on June 24, 2015, 11:37:43 pm
Of course Slakewell..that is hygroscopic...the ability to extract moisture from the air..
Title: Re: 87 CR250 front brake
Post by: Slakewell on June 25, 2015, 07:47:55 am
Sorry had spell check set on irony  ;)
Title: Re: 87 CR250 front brake
Post by: Photomike666 on October 10, 2015, 03:04:45 am
You wonder why 30 year brake fluid is shit and the pads are clazed?
You dont think as a hydrospoic fluid it dosent have some water after all this time?
One mornings work should fix your problems.
I would anti seize the pistons in clapitor as well

I understand the old consumables are shite - was really asking if the stock unit was adequate or if an upgrade would be better than a stock rebuild.
Title: Re: 87 CR250 front brake
Post by: Photomike666 on October 10, 2015, 03:13:55 am
Mate the caliper pistons are 'seized' that's why the lever is hard but the brakes are crap.Seen it heaps.

Why? because when a bikes sits around the brake fluid turns to mud and crap gets behind the seals pressing then against the pistons and making them tight, they aren't really seized, just uber tight.
Cure ? Easy just get a new caliper seal kit, they are really cheap and as far as I know they fit Honda CR's 125/250/500  from '84 to '01 or later- same seals.

You don't even have to remove the brake hose, use the lever to pump out the pistons-clean the caliper (spotless) fit new seals, (lube seals after words) install clean pistons.
Hold the caliper above the master cylinder to let the air go up, put something like a block of wood between the pistons and caliper body, bleed in that position.
Refit the caliper and ride.  8)

Thanks for the info. 

I'm certainly going to be giving the master cylinder a refresh; but the calliper has stuffed bolt hole so I'll be replacing the calliper - question is do I go stock or look for something a bit more effective.  This restoration is going to be ridden, so first areas to get sorted are going, stopping and handling.  Cosmetics can come later :)

My just finished '87 CR500 resto.

(http://i115.photobucket.com/albums/n309/gtr_05/crfin2_zpswbd8j4bi.jpg) (http://s115.photobucket.com/user/gtr_05/media/crfin2_zpswbd8j4bi.jpg.html)
Title: Re: 87 CR250 front brake
Post by: PEZBerq on October 10, 2015, 08:33:31 am
Very nice resto Mr500. Well done  8)