1978 GL1000 brakes


Information and questions on GL1000 Goldwings (1975-1979)
  • Sponsored Links
pogo3033
Posts: 6
Joined: Mon Feb 17, 2014 5:09 pm
Location: Fort Myers
Motorcycle: 1978 GL1000

1978 GL1000 brakes

Postby pogo3033 » Wed Apr 30, 2014 1:22 pm



Hi, I have a 1978 GL1000 that has sat for a long period of time. I have removed and rebuilt the front and rear master cylinders. My current problem is with the rear master cylinder, I cannot get it to bleed. I have had the piston out several times, polished the inside of the cylinder and reassembled. When I push the piston down it will stay stuck at the bottom and not return so I can see that it will not pump fluid if it stays stuck at the bottom of the stroke. My question is how free should the piston be? Should the pressure from the spring return the piston to the stop washer? I can use air pressure to pop it back up but the first time I push on the pedal the piston stays at the bottom of it's stroke.

I have assembled it according to the Honda service manual. Actually I have two GL1000's and the same problem exists on both,,,what can I do to free up the piston and primary cup?



User avatar
WingAdmin
Site Admin
Posts: 17047
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: 1978 GL1000 brakes

Postby WingAdmin » Wed Apr 30, 2014 7:07 pm

pogo3033 wrote:Hi, I have a 1978 GL1000 that has sat for a long period of time. I have removed and rebuilt the front and rear master cylinders. My current problem is with the rear master cylinder, I cannot get it to bleed. I have had the piston out several times, polished the inside of the cylinder and reassembled. When I push the piston down it will stay stuck at the bottom and not return so I can see that it will not pump fluid if it stays stuck at the bottom of the stroke. My question is how free should the piston be? Should the pressure from the spring return the piston to the stop washer? I can use air pressure to pop it back up but the first time I push on the pedal the piston stays at the bottom of it's stroke.

I have assembled it according to the Honda service manual. Actually I have two GL1000's and the same problem exists on both,,,what can I do to free up the piston and primary cup?


The spring should easily push the piston back out - in fact, you should have a considerable amount of force from that spring - enough that it is very difficult to depress it with just your finger. Something is definitely wrong.

User avatar
Placerville
Posts: 423
Joined: Tue Mar 09, 2010 12:58 pm
Location: Placerville, CA
Motorcycle: 1976 Naked Yellow

Re: 1978 GL1000 brakes

Postby Placerville » Wed Apr 30, 2014 9:18 pm

I'm not sure I'm on the right track for this one but, is it possible that the 'spooge' hole may be the problem? If it's clogged, it would prevent (in this case) air from entering the cylinder thus restricting the release of the piston. Both the front and rear masters have them. (Very small hole at lower right.)

Image
Placerville- 1976 Yellow
Image

User avatar
WingAdmin
Site Admin
Posts: 17047
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: 1978 GL1000 brakes

Postby WingAdmin » Wed Apr 30, 2014 9:50 pm

Placerville wrote:I'm not sure I'm on the right track for this one but, is it possible that the 'spooge' hole may be the problem? If it's clogged, it would prevent (in this case) air from entering the cylinder thus restricting the release of the piston. Both the front and rear masters have them. (Very small hole at lower right.)

Image


Air is not supposed to enter the cylinder. The master cylinder piston should retract easily from the spring. If there is a vacuum, it should suck fluid from the reservoir to fill the cylinder, not air.

User avatar
Placerville
Posts: 423
Joined: Tue Mar 09, 2010 12:58 pm
Location: Placerville, CA
Motorcycle: 1976 Naked Yellow

Re: 1978 GL1000 brakes

Postby Placerville » Wed Apr 30, 2014 9:58 pm

WingAdmin wrote:
Placerville wrote:I'm not sure I'm on the right track for this one but, is it possible that the 'spooge' hole may be the problem? If it's clogged, it would prevent (in this case) air from entering the cylinder thus restricting the release of the piston. Both the front and rear masters have them. (Very small hole at lower right.)

Image


Air is not supposed to enter the cylinder. The master cylinder piston should retract easily from the spring. If there is a vacuum, it should suck fluid from the reservoir to fill the cylinder, not air.


I Agree. He has his M/C off the bike and they're not filled with fluid at this time. In my description, I said, "in this case" meaning, that the hole would now be sucking air instead of fluid. Therefore, is the piston not able to spring back because the hole is clogged?
Placerville- 1976 Yellow
Image

User avatar
WingAdmin
Site Admin
Posts: 17047
Joined: Fri Oct 03, 2008 4:16 pm
Location: Strongsville, OH
Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: 1978 GL1000 brakes

Postby WingAdmin » Wed Apr 30, 2014 10:09 pm

No, the very small hole on the right is the one that allows fluid to return from the caliper when it heats up (or when the caliper piston is retracted). The larger hole on the left is the one that leads to the reservoir.

User avatar
Placerville
Posts: 423
Joined: Tue Mar 09, 2010 12:58 pm
Location: Placerville, CA
Motorcycle: 1976 Naked Yellow

Re: 1978 GL1000 brakes

Postby Placerville » Thu May 01, 2014 9:52 am

Well, then I'm stumped on this one. Odd that he has the same problem with two bikes.
Placerville- 1976 Yellow
Image

pogo3033
Posts: 6
Joined: Mon Feb 17, 2014 5:09 pm
Location: Fort Myers
Motorcycle: 1978 GL1000

Re: 1978 GL1000 brakes

Postby pogo3033 » Thu May 01, 2014 6:30 pm

Thanks for the advice and I'm still workin' on it. I will take some pictures and post them later.

****

pogo3033
Posts: 6
Joined: Mon Feb 17, 2014 5:09 pm
Location: Fort Myers
Motorcycle: 1978 GL1000

Re: 1978 GL1000 brakes

Postby pogo3033 » Sun Jun 01, 2014 12:34 pm

Well I worked and worked on the old master cylinder for the GL1000 but never could get it to work. I finally ordered a used one from an Ebay store that the guy said was frozen and was just for parts, so when I got it I tore it apart and cleaned it and reassembled it and hooked it up and it worked fine. So I got the problem fixed on one of the bikes, the other one I ordered an aftermarket master cylinder that was meant for a Honda 500cc something or other and made a bracket to mount it and it solved my problem with the original equipment master cylinders. I think I spent more time on the brakes than anything else.
Attachments
Aftermarket master cylinder installed on 1978 GL1000
Aftermarket master cylinder installed on 1978 GL1000

SnoBrdr
Posts: 326
Joined: Fri Mar 07, 2014 9:01 am
Location: Providence, Rhode Island
Motorcycle: 1978 GL 1000

129K Original Owner

Re: 1978 GL1000 brakes

Postby SnoBrdr » Sun Jun 01, 2014 6:24 pm

pogo3033 wrote:Well I worked and worked on the old master cylinder for the GL1000 but never could get it to work. I finally ordered a used one from an Ebay store that the guy said was frozen and was just for parts, so when I got it I tore it apart and cleaned it and reassembled it and hooked it up and it worked fine. So I got the problem fixed on one of the bikes, the other one I ordered an aftermarket master cylinder that was meant for a Honda 500cc something or other and made a bracket to mount it and it solved my problem with the original equipment master cylinders. I think I spent more time on the brakes than anything else.


That's the rear?

How well does it work and where did you get it from.

Pics of the bracket too please !

A link of some kind would be very helpful.

pogo3033
Posts: 6
Joined: Mon Feb 17, 2014 5:09 pm
Location: Fort Myers
Motorcycle: 1978 GL1000

Re: 1978 GL1000 brakes

Postby pogo3033 » Mon Jun 02, 2014 10:23 am


pogo3033
Posts: 6
Joined: Mon Feb 17, 2014 5:09 pm
Location: Fort Myers
Motorcycle: 1978 GL1000

Re: 1978 GL1000 brakes

Postby pogo3033 » Mon Jun 02, 2014 10:27 am

http://www.amazon.com/shops/A1EPE8GMWC6QK5/ref=aag_d_sh


Link address for 50 Caliber Racing Products through Amazon.

$40 was what I paid
I have not ridden the bike as of yet but with it on the center stand the brake worked just fine. I used a spare one piece brake line that was for a front brake and did away with the 2 piece Honda brake line.
Mount was one of the original mount holes for the Honda master cylinder and a piece of 1/8" X 1 1/2" flat aluminum stock that I had on hand but came either from Lowes or Home Depot..

Picture on the web, the reason I ordered this one was that it had the dimensions shown.
Picture on the web, the reason I ordered this one was that it had the dimensions shown.

SnoBrdr
Posts: 326
Joined: Fri Mar 07, 2014 9:01 am
Location: Providence, Rhode Island
Motorcycle: 1978 GL 1000

129K Original Owner

Re: 1978 GL1000 brakes

Postby SnoBrdr » Mon Jun 02, 2014 11:06 am

pogo3033 wrote:http://www.amazon.com/shops/A1EPE8GMWC6QK5/ref=aag_d_sh


Link address for 50 Caliber Racing Products through Amazon.

$40 was what I paid
I have not ridden the bike as of yet but with it on the center stand the brake worked just fine. I used a spare one piece brake line that was for a front brake and did away with the 2 piece Honda brake line.
Mount was one of the original mount holes for the Honda master cylinder and a piece of 1/8" X 1 1/2" flat aluminum stock that I had on hand but came either from Lowes or Home Depot..

Rear master cylinder..jpg


Looks pretty sweet, hope it works fine.

I asked cause I am always looking forward as far as needing parts.




Return to “GL1000 Information & Questions”




Who is online

Users browsing this forum: smittyboy734 and 3 guests