Clutch fading


Information and questions on GL1500 Goldwings (1988-2000)
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BIGBopper1956
Posts: 9
Joined: Fri Apr 12, 2019 12:40 am
Location: Palm Springs, CA
Motorcycle: 1993 GL 1500 Aspencade
1999 GL 1500 Valkyrie Interstate
1999 GL 1500 Valkyrie Tour
1999 GL 1500 Valkyrie Standard
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Clutch fading

Post by BIGBopper1956 »



Finishing up my 1993 GL 1500A and facing an issue I can not find advice on. Sorry, searched long before taking up peoples time. Bike sat for 8 years in a climate controlled environment before I purchased it. When brought home it had no brakes, no clutch, needed a carbs rebuild, along with other general service maintenance. Bled the brakes, and the clutch, and everything responded well. That is while sitting in the garage! Changed the oil, Rotella T5 10-40 along with all fluids with new DOT 4. Everything looks clean and there doesn't appear to be any air in the system. Took it out the other day rode it around the block and then got a phone call. Sat for about 10 minutes talking with bike running in neutral. When finished put it in gear (no issues), released the clutch and nothing. Bike would not move. Pushed it in the garage, continued bleeding the clutch with Mighty Vac and it appeared all air was gone. Took it out again, rode it about 10-15 minutes before beginning to notice some slippage. Brought it in again, cleaned out the master cylinder, and began again to bleed using new fluid. Did notice more air and felt I was making progress. Took it out again, this time about 30 minutes on a very hot day (about 100) Palm Springs, CA and at this point noticed it slipping. I always have good pressure at the lever, but the point of engagement changes from what I would say is a normal (about halfway) point to gradually not engaging until the lever is nearly completely released. Shifting is very smooth, and clutch feels very good until it begins to warm up, and the slipping begins.

At this point am considering a slave, and master cylinder rebuild. Am I headed in the right direction?


BIG Bopper
Tim Bannister

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Happytrails
Posts: 963
Joined: Wed Sep 04, 2013 6:13 pm
Location: Natrona Hgts, Pennsylvania
Motorcycle: 1991 Goldwing 1500 SE
2018 Ural Gearup

Re: Clutch fading

Post by Happytrails »

Yes to both. You might find the slave is the worse of the two. Its not unusual for this to happen they just occasionally need cleaned up/rebuilt.



1991 GL1500 SE Anniversary Edition
Sun Flare Gold Metallic
Vallant Brown Inset

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gipsy42
Posts: 136
Joined: Sat Jun 12, 2010 8:58 pm
Location: Villa Adelina, Bs.As. Argentina
Motorcycle: 1993 GL1500 SE
1978 GL1000
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Re: Clutch fading

Post by gipsy42 »

May I suggest that before you do anything farther, try this simple test:
take her out for a ride, let her warm enough until the clutch slips, then pull the clutch lever and reinstalling it, …..did it get back to normal??
If so, you're having a pressure build up due to the bled hole in master cylinder is blocked, probably the PO changed the levers and the contact point to the pusher rod is too long, thus the piston in not full retracting causing the bled hole to became blocked.
Mario
aka Gipsy42
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I just regrets the things I haven't done.

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bellboy40
Posts: 756
Joined: Fri Nov 27, 2009 1:13 pm
Location: Brewton, AL
Motorcycle: 2000 GL1500SE Candy Spectra Red

Re: Clutch fading

Post by bellboy40 »

It sounds to me like the return hole in the clutch master cylinder is blocked with some crud from the old fluid that has been sitting in there for many years. Remove most of the fluid from the master cylinder and down in the bottom is a small cover over the return hole. Remove the cover and take a very small wire (one bristle from a wire brush) and poke through it to open up the hole. Try that and see if it gets your clutch working properly. Also, as has already been mentioned, you should take the clutch slave cylinder off and rebuild it. I can guarantee it will have a bunch of crud in it also.

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754
Posts: 109
Joined: Fri Sep 08, 2017 9:08 am
Location: Clermont Ga
Motorcycle: 1992 GL1500 Interstate

1978 CB750 Supersport

Re: Clutch fading

Post by 754 »

I agree it may be that the return hole my be clogged. Also to remove air and bleed the system I like to reverse bleed the system. Take the cover off the clutch master cylinder and suction some of the fluid out. Get a large syringe, rubber hose and fresh brake fluid. Pull the plunger out and fill it with fluid and put the plunger back in. Then use the hose to connect the syringe to the slave bleeder. Open the bleeder and slowly push the brake fluid into the system, (watch the master as it will fill back up with fluid). You should see air bubbles (air prefers to rise), it should also help to clear the return passage as well.
1992 Goldwing Gl1500 Interstate

1978 CB750 Supersport

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bluthundr31
Posts: 560
Joined: Tue Jul 11, 2017 11:43 pm
Location: Morgan Hill, CA.
Motorcycle: 1991 GL1500 Interstate (Cinnamon Beige)

Re: Clutch fading

Post by bluthundr31 »

Remove the cap, and the plastic plate, and the rubber boot on the reservoir (left handlebar). Gently pry up the shiny "tab" at the back and use the smallest "torch tip" to poke into the return hole and clean that gunk out. Once the hole is cleaned out, put in fresh DOT4 and bleed the clutch. You'll be fine (crossing fingers for ya).

BIGBopper1956
Posts: 9
Joined: Fri Apr 12, 2019 12:40 am
Location: Palm Springs, CA
Motorcycle: 1993 GL 1500 Aspencade
1999 GL 1500 Valkyrie Interstate
1999 GL 1500 Valkyrie Tour
1999 GL 1500 Valkyrie Standard
Contact:

Re: Clutch fading

Post by BIGBopper1956 »

This is a phenomenal forum and so much great advice. I am in the process of doing all the suggestions. So far pulled the slave cylinder and just finished cleaning some nasty pieces. Kit will arrive Friday. Pulling the master cylinder and will do the same thing. Clean, clean, clean, then poke at the pressure return hole (sewing needle works great) and rebuild when kit arrives Friday. Have never done a reverse bleed, but have a big syringe and tubing so will give it a try. Will update when complete. Thanks again


BIG Bopper
Tim Bannister

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