R75/5 fork drain problem. yikes!

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MikeGeee
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R75/5 fork drain problem. yikes!

Post by MikeGeee » Mon Jan 08, 2018 7:11 pm

Hi all,

I just bought my first airhead and i'm really excited. As is customary with 45-year-old+ bikes, though, it's been needing a lot of attention. But after consulting my Clymer manual, scouring the web (including this here forum) and racking my brain, I can't figure it out.

So: my front end ZERO hydraulic pressure. It is super springy or "washy" or "splashy" or whatever term you want to use. It's just terrible.

I held the 4mm allen bolt in place and unspun the 13mm nut at the bottom of the fork. Then I undid the for cap on top. ZERO oil came out the bottom. Tried the other fork, some result. "OK", I thought. "No oil in there. I'll just fill it up."

I don't have access to a lift, so I had my bike was on the center stand. In this situation, the Clymer calls for 265cc. I decided on 250cc just to be safe. I poured in about half of that amount when it started overflowing from the top. What the heck?!

Are my fork drains clogged or something? I'm I just getting the procedure wrong?

One more suspicious thing: before doing this, I stuck a dowel down the fork tube. There seemed to be about 2.5 inches of oil, but the oil was silvery in color. That can't be good, right?

I appreciate all responses that don't call me stupid, insult other answers, etc..

Thanks in advance!
1972 BMW R75/5 Toaster
1976 Honda CB200t
1948 Harley Davidson WL45

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jagarra
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Re: R75/5 fork drain problem. yikes!

Post by jagarra » Mon Jan 08, 2018 7:25 pm

There may be some bumpers located in the forks that deteriorate over time causing the blockage. If it were me I would pull the sliders off the forks and have a look see in there. A good cleaning of the contaminants and possible replacing of a few parts may get you back in business.
1974 R90/6 built 9/73
1994 BMW R1100RS
1964 T100SR Triumph
1986 Kawasaki Concours

Kurt in S.A.
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Re: R75/5 fork drain problem. yikes!

Post by Kurt in S.A. » Mon Jan 08, 2018 8:27 pm

On my /7, you have to push the center rod, the one you put the allen wrench into, up inside the fork. You'll be fighting the spring pressure to do that. Best to have the bike on the center stand as the spring will be fully extended. Once it's drained, you'll need to wriggle the center rod back into the hole in the bottom of the leg. Put the bolt back on the rod. Be sure that one side is done draining with the bolt back in place before you attack the other leg. Otherwise, your $20 fluid change turns into a $100+ job. DAMHIK.

Kurt in S.A.

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Zombie Master
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Re: R75/5 fork drain problem. yikes!

Post by Zombie Master » Tue Jan 09, 2018 1:30 am

Just take the units apart and rebuild. That's the shortest distance from A to B IMO
BTW include year and model for better answers.
Any and all disclaimers may apply

Rob
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Re: R75/5 fork drain problem. yikes!

Post by Rob » Tue Jan 09, 2018 2:14 am

Rebuild was going to be my suggestion, as well.

Hey Mike! Did you add your garage to your signature after ZM's comment? I really like the CB200 series. I had one for a little while. Welcome!
Rob V

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MikeGeee
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Re: R75/5 fork drain problem. yikes!

Post by MikeGeee » Tue Jan 09, 2018 11:32 am

Thanks for the replies, everyone. My signature was actually there the whole time. And yeah, the CB200 is an awesome little bike. So incredibly reliable. Pretty much the exact opposite of the WL45...

Anyhow, after using a car jack to get a little more space out of the front forks, I was able to drain one of them... but the other one would not drain. I filled the one that drained and topped off the other one, but there's no perceivable improvement.

Of course rebuilding is always on option, and I suppose it will be my fate, but I was looking for the simplest answers first, especially since I don't have a motorcycle lift... or a job.

I just moved to the West Coast and this bike was a present from me to myself for doing so.
1972 BMW R75/5 Toaster
1976 Honda CB200t
1948 Harley Davidson WL45

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Steve in Golden
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Re: R75/5 fork drain problem. yikes!

Post by Steve in Golden » Tue Jan 09, 2018 1:43 pm

Zombie Master wrote:
Tue Jan 09, 2018 1:30 am
BTW include year and model for better answers.
He's got a toaster ZM. :twisted:
Mike wrote: I appreciate all responses that don't call me stupid, insult other answers, etc..
We don't call people stupid or insult them around here. Not usually anyway. Welcome aboard Mike!

Rob
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Re: R75/5 fork drain problem. yikes!

Post by Rob » Tue Jan 09, 2018 3:05 pm

Steve in Golden wrote:
Tue Jan 09, 2018 1:43 pm
Zombie Master wrote:
Tue Jan 09, 2018 1:30 am
BTW include year and model for better answers.
He's got a toaster ZM. :twisted:
I really wanted to include a link to Heywood Banks tune, Toast, but ZM reprimanded me the last time I had fun on the front page.

You will have to Google it, yourself, if you are curious.
Rob V

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Zombie Master
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Re: R75/5 fork drain problem. yikes!

Post by Zombie Master » Tue Jan 09, 2018 11:48 pm

What's a toaster?
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MikeGeee
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Re: R75/5 fork drain problem. yikes!

Post by MikeGeee » Wed Jan 10, 2018 4:23 pm

It's step 2 of preparing an English muffin
1972 BMW R75/5 Toaster
1976 Honda CB200t
1948 Harley Davidson WL45

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