Author Topic: building pressure brake master cylinder  (Read 1249 times)

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Offline Djfob

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building pressure brake master cylinder
« on: September 14, 2013, 05:09:38 PM »
For the life of me I cannot build any pressure in the brake lever to bleed the brakes. Brand new nissin brake master, banjo bolt and two copper washers, steel braided line, caliper hard line, bleeder, caliper seal and phenolic piston.

All brand new parts with pads. The pad on the piston side was so tight I had to tap it in. Not sure if that matters.
78 CB750k

Offline hellraiserDLX

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Re: building pressure brake master cylinder
« Reply #1 on: September 14, 2013, 05:38:40 PM »
The pad shouldn't be that tight. Ou should lube the sides of the pad too so it doesn't lock up after getting hot. I cupped my hand over the reservoir and blew into it to start building a bit of pressure and then just pump pump pump bleed repeat :) others might say I'm wrong but it worked splended on my 550. 15 minutes tops

Offline Djfob

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Re: building pressure brake master cylinder
« Reply #2 on: September 14, 2013, 06:02:13 PM »
I ended up using a syringe to bleed from the bleeder up to the master. Brakes have pressure now but the new pads seem to drag.

78 CB750k

Offline Viktor.J

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Re: building pressure brake master cylinder
« Reply #3 on: September 15, 2013, 12:02:01 AM »
if you renovated the calipers and have a new MC, the brakes def. shouldn't drag...
Please ! Take a look and give me feedback in my project thread, its much needed :)
http://forums.sohc4.net/index.php?topic=112745.0

Honda CB750 K2

Offline Djfob

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Re: building pressure brake master cylinder
« Reply #4 on: September 15, 2013, 10:22:32 AM »
Going to take a dremel to the pad for some extra clearance to see if that helps
78 CB750k

Offline flybox1

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Re: building pressure brake master cylinder
« Reply #5 on: September 15, 2013, 11:18:13 AM »
If the metal backer of your new pad was painted black, you'll need to take a wire wheel to it and remove all the paint down to metal on the outside.  This will give you the clearance you need.
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Offline thirsty 1

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Re: building pressure brake master cylinder
« Reply #6 on: September 15, 2013, 11:29:30 AM »
I bleed the brakes with the caliper off the fork legs with the pads pushed all the way in. I use pieces of wood and some shims for installing doors and windows. This eliminates all most all of the air in the caliper. Then I install the caliper and repeat the bleeding process. I clean off all the paint from the pads too.
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Offline skidooextreme

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Re: building pressure brake master cylinder
« Reply #7 on: September 15, 2013, 12:36:56 PM »
build pressure in the master by taking the line off and putting your finger over the outlet hole until fluid starts squrting out and then attach the line

Offline Djfob

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Re: building pressure brake master cylinder
« Reply #8 on: September 15, 2013, 10:05:37 PM »
If the metal backer of your new pad was painted black, you'll need to take a wire wheel to it and remove all the paint down to metal on the outside.  This will give you the clearance you need.

Haven't gotten around to taking it apart yet but I do recall these EBC pads being black
78 CB750k

Offline Djfob

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Re: building pressure brake master cylinder
« Reply #9 on: September 15, 2013, 10:06:53 PM »
The pad shouldn't be that tight. Ou should lube the sides of the pad too so it doesn't lock up after getting hot. I cupped my hand over the reservoir and blew into it to start building a bit of pressure and then just pump pump pump bleed repeat :) others might say I'm wrong but it worked splended on my 550. 15 minutes tops

What lube should be used on the sides of the pad?
78 CB750k