brake fluid change


Technical information and Q&A applicable to all years and models of Goldwings
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hap2
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brake fluid change

Post by hap2 » Wed May 30, 2018 10:38 pm



I was told that the diaphragm in the brake reservoir needs to be changed every time the brake fluid is bled or changed? Is that correct? Y or Y not? I just changed the clutch fluid & didn't have a need to change the diaphragm.



DaveO430
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Re: brake fluid change

Post by DaveO430 » Thu May 31, 2018 5:49 am

That's a new one on me.

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Re: brake fluid change

Post by DenverWinger » Thu May 31, 2018 7:17 am

Diaphragm???????????
(20 chars) :mrgreen:
They say 98% of all Hardleys ever made are still on the road..... The other 2% made it home. :lol:
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Re: brake fluid change

Post by WingAdmin » Thu May 31, 2018 7:48 am

The diaphragm in the master cylinder is this rubber piece:

Image

Its job is to keep outside air separate from the brake fluid. As the brake fluid goes up and down (mostly down, as the brakes wear), it expands into the reservoir. Air fills the space above it. Because brake fluid is hygroscopic (absorbs moisture from the air), the diaphragm serves to keep the moist air from contaminating the brake fluid.

I have NEVER heard of replacing this during brake fluid changes. I will take mine out, hose it off with some brake cleaner, and reinstall it - that's it.

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Re: brake fluid change

Post by hap2 » Thu May 31, 2018 9:31 am

Ya, I agree with u...but the Haynes Owner's Workshop manual says change. I think, like u, I'll just hose it off & b done with it.

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hap2
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Re: brake fluid change

Post by hap2 » Thu May 31, 2018 9:35 am

Is changing the brake fluid for both front & rear brakes on a 1500 similar to changing the clutch fluid? I've usually just paid someone to do it, but may not thjs time.

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Re: brake fluid change

Post by WingAdmin » Thu May 31, 2018 9:56 am

hap2 wrote:
Thu May 31, 2018 9:35 am
Is changing the brake fluid for both front & rear brakes on a 1500 similar to changing the clutch fluid? I've usually just paid someone to do it, but may not thjs time.
Pretty much identical, yes. The only difference is that with the rear brake pedal, the reservoir has a small screw cap, and you must first flush the front left brake caliper, then the rear brake (the rear brake pedal actuates both).

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Re: brake fluid change

Post by WingAdmin » Thu May 31, 2018 9:57 am

hap2 wrote:
Thu May 31, 2018 9:31 am
Ya, I agree with u...but the Haynes Owner's Workshop manual says change. I think, like u, I'll just hose it off & b done with it.
I would view any information published in a Haynes manual with extreme suspicion. :)

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Re: brake fluid change

Post by hap2 » Thu May 31, 2018 10:12 am

What manual (other than Haynes) wud u suggest then?

I tend u agree with u cuz in the Haynes, it says the round reservoir (by the battery), supplies fluid to both the rear and front brakes. If that is so, what's the reservoir on the right handlebar (by the hand lever for the front brake) for?

I REALLY appreciate all the help offered on this 'channel'.

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Re: brake fluid change

Post by hap2 » Thu May 31, 2018 10:16 am

I apologize. I just read the reservoir up on the right side of the handlebar is for the front brake & the one down by the battery is for the rear brake. Is that correct?

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Re: brake fluid change

Post by WingAdmin » Thu May 31, 2018 11:05 am

hap2 wrote:
Thu May 31, 2018 10:12 am
What manual (other than Haynes) wud u suggest then?

I tend u agree with u cuz in the Haynes, it says the round reservoir (by the battery), supplies fluid to both the rear and front brakes. If that is so, what's the reservoir on the right handlebar (by the hand lever for the front brake) for?

I REALLY appreciate all the help offered on this 'channel'.
The Honda OEM manual, definitely. It's by far the best one.

The round reservoir and rear brake pedal/master cylinder actuate the rear brake caliper as well as the left front caliper. The reservoir and brake lever on the handlebar actuates the right front caliper only. This is why when bleeding/flushing the rear brakes, you bleed the left front caliper first, then the rear caliper.

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Re: brake fluid change

Post by jeffcosmo » Thu May 31, 2018 8:49 pm

hap2 wrote:
Thu May 31, 2018 10:12 am
What manual (other than Haynes) wud u suggest then?
Simply put, the manual put out by the manufacturer of ANY vehicle is the Gold Standard. This IS the manual by which your vehicle is put right during any warrantee service and is the manual used by the dealer.
As I often say, the folks that screwed it together should know how to fix it.
That said, I have factory manual for nearly every vehicle I own (Avalon's is coming). And I could NOT have repaired the electronic shifting on my daughter's Camry without the Toyota Manual (especially the wiring diagram).

Still, Haynes is better than Chilton M/C manuals...like Pabst is better than Hamm's...but both taste like bear piss - after said bear has eaten asparagus...

Cosmo



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