# Hayes 9 bleeding and adjusting



## kwest10 (Jun 7, 2006)

I thought I was fairly competent when it comes to mechanics. At least on cars and I didn't think these disc brakes would be so complicated.
The Hayes instructions stink to high hell and the illustrations are useless. I tried bleeding my own Hayes 9's and can't do squat. Anyone have better instructions or a pictoral? thanks.


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## XSL_WiLL (Nov 2, 2004)

Use a HUGE syringe. Degas the fluid in the syringe. Push fluid through the caliper bleed nut. Force it out the bleed hole at the lever (pointed up). Have the fitting in place with something to catch the overflow. Keep going till no more bubbles come out, or before you run low on fluid in the syringe. You may need to tap the lines to get stubborn bubbles.


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## oldskoolbiker (Jun 2, 2005)

Also make sure you have the lever as high as possible, and the caliper as low as possible. In addition to flipping the brake like a few times to get air bubbles out, I also actuate the lever a few times also. A syringe will work better, but I haven't had any problems with the bottle. Try putting a small zip tie around the hose where you inserted onto the bleeder valve, that will get a pretty tight seal on there.


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## dogonfr (Jan 6, 2005)

Be shure the master is pointed up & is the highest point, your bleeding up hill on these puppies. This pic is in the normal possition because i was to lazy to rotate for a pic. If you have a problem with hose expanding from the fluid go to the pet store & get air hose for a fish tank, works awsome & the fluid doesn't cause it to swell for a long time.


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## kwest10 (Jun 7, 2006)

I don't know which bolts to loosen etc. The instructions have no illustration as to where the bleeder screws are at and what not. I know the caliper from the MC but other than that I don't. I've never worked with disc brakes on a bike.


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## dogonfr (Jan 6, 2005)

On the caliper there is a hex tube with a rubber cap, that is were the fluid goes in. Looking at the master on the right is the lever then a phillips screw then a plug, remove the plug & install a bleed addapter & hose going to a catch tank. The HFX-9 has the blader directly under the plug so you need to push it in very straight, it sux.


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## blue_neon (Jun 7, 2005)

With your bleed kit you should cut the hose in two aswell.

For the lever, you use the silver adapter that comes with the kit. Plug that one end into the hose tightly, then using a phillips head screwdriver, pry the rubber cap off that is between the two hex screws. This cap just prys off and on so dont worry.

Then insert the fitting into that hole, run the rest of the hose into an overflow bucket like shown above.

-----

At the Caliper, with the second bit of hose you have cut (this should be much smaller in length though) fit it to either the bleed bottle OR the syringe (which ever way you want to do it). The other end of the hose will just fit nicley over the 'plug' on the caliper, just make sure its seated.

Before openeing the bleed valve at the caliper, remove the air in the hose connected to etiher the bottle of syringe. The using a 6mm i think spanner end open the bleed valve 1/4 turn to 1/2 turn...now you can follow the instructions Hayes have given you and you should be right.


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## JimboCO (May 3, 2005)

Thanks to all that have posted on this thread, especially blue-neon. Good info here.
Jim


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## abraham (Aug 12, 2006)

have done all this with copious amounts of brake fluid squirting all over an antique asian rug, I'd cycle off sharpish before my wife comes in and sees the mess but my brakes are still as spongy as santas sac the day after christmas.Does it help if the hose runs uphill all the way to top bleed hole?


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## MikeDee (Nov 17, 2004)

kwest10 said:


> I thought I was fairly competent when it comes to mechanics. At least on cars and I didn't think these disc brakes would be so complicated.
> The Hayes instructions stink to high hell and the illustrations are useless. I tried bleeding my own Hayes 9's and can't do squat. Anyone have better instructions or a pictoral? thanks.


What I have found out is that you can not remove all the air from the system by pushing it in the caliper and letting it flow out the lever. You also have to pull a suction on the caliper to get entrapped air out. This is key. This is explained in the Hayes bleed instructions by squeezing the bottle for 5 seconds, and letting it return to its original shape to draw air out. You can do the same with a syringe. I found this out the hard way after much time was wasted. Another tip with the Hayes bleed kit that isn't covered in the instructions: slide the spring on the end of the bottle hose, put the hose on the bleeder fitting, and slip the spring over fitting. It keeps the hose on the fitting so it doesn't come off and make a mess.


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## Jet-Mech (Feb 21, 2006)

kwest10 said:


> IAnyone have better instructions or a pictoral? thanks.


Ask and Ye shall receive Kwest10. Courtesy of Australian Mountain Bike magazine :thumbsup: .


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## dogonfr (Jan 6, 2005)

Nice article there JM :cornut: :thumbsup:


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## MikeDee (Nov 17, 2004)

2 problems I see: They say to remove the caliper from the bike but the illustrations show it clearly attached. Also, they do not pull a suction on the caliper to remove entrapped air, like the Hayes manual says. Perhaps if the caliper were properly oriented the air can be pushed out to the lever; don't know. The bit about the old pads and spacer is good, as you can easily pump out a piston by stroking the lever, with the bleed screw open and pressure applied to the syringe (happened to me).


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## aznsap (Jul 7, 2006)

this looks a lot easier to do than bleeding brakes on a car.

when are you supposed to bleed the brakes on a bike?


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## Jet-Mech (Feb 21, 2006)

aznsap said:


> this looks a lot easier to do than bleeding brakes on a car.
> 
> when are you supposed to bleed the brakes on a bike?


I was actually thinking the other way Aznsap. Bleeding car brakes is easy, just pour fluid into the reservoir, press the pedal, open the bleed screw on the caliper to let fluid through, retighten the bleed screw, release the pedal and repeat. All you need is brake fluid, a short length of clear plastic hose, an old plastic bottle and a ring spanner.

I am constantly amazed by the myriad of complex techniques and equipment needed to bleed bike brakes given that they are very similar to car brake systems in principle. The technique and equipment required to bleed Juicy's makes you think that you are performing open heart surgery with electron microscopes  .


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## Too Rass Goat (Sep 16, 2005)

Following JM's post, I just bled my 9's and replaced the pads for the 1st time. It couldn't be any more simple, thanks for the post. Haye's instructions in the bleed kit do kind of suck. I also bypassed the supplied bottle and went right to a syringe. It was too easy.


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## dogonfr (Jan 6, 2005)

aznsap said:


> this looks a lot easier to do than bleeding brakes on a car.
> 
> when are you supposed to bleed the brakes on a bike?


I find doing brakes on a moto so much easier than a bike, like JM says it's like performing heart surgery.

Realisticly you should be replacing the fluid once a year, i probibly do it every 2 years if im not feeling lazy.


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## 95Stumpy (Jul 29, 2005)

I have to trim my brake line. Would it be easier to bleed the brake off bike?


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## dogonfr (Jan 6, 2005)

95Stumpy said:


> I have to trim my brake line. Would it be easier to bleed the brake off bike?


If your sneaky you may not have to bleed the line. Make shure all open mouths are facing up.


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## don_w (Oct 14, 2008)

What causes the brake to squirt fluid out the front of the lever unit? (out of the bleed/overflow hole I think)


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## dogonfr (Jan 6, 2005)

don_w said:


> What causes the brake to squirt fluid out the front of the lever unit? (out of the bleed/overflow hole I think)


What model brake do you have??


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## don_w (Oct 14, 2008)

Hayes Nine


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## dogonfr (Jan 6, 2005)

don_w said:


> Hayes Nine


Did you bleed them recently and are you loosing pressure??


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## don_w (Oct 14, 2008)

Have never bled them (but I'm going to), yes pressure was lost. After a few pumps, there was nothing cos all the fluid had squirted out the front


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## sivesind (Apr 22, 2009)

*Thanks a mill!*



Jet-Mech said:


> Ask and Ye shall receive Kwest10. Courtesy of Australian Mountain Bike magazine :thumbsup: .


JM: I cannot tell how grateful I am! I struggled with the Hayes service manual, which is misleading at best. My brakes are now nice and firm, job done in five minutes. Short description:
1. Caliper horizontal!
2. Open caliper nipple with pressure on syringe
3. Force fluid in with syringe, until no bubbles at master cylinder
4. Close caliper nipple while maintaining pressure on syringe
5. Pump lever until firm
6. Repeat 2-5 until no more bubbles and lever stays firm
7. Ride happily, while sending thankful thoughts to JM:thumbsup:

/Lars


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## Paul1977 (Aug 9, 2007)

Sounds like youve lost the plug from the master cylinder


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## king_andre (Feb 16, 2009)

I am having trouble with my Hayes El Camino's. Does anyone have any tips for these suckers? So far my only success is getting the oil everywhere. I have tried in vein to follow the instructions from Hayes but nothing. Any assistance would be appreciated.


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## coop3422 (Jul 12, 2006)

bringing this back from the dead but my Nine's are really soft and my buddy just got a bike with Nines and his are super firm, which I want. And the past few rides I've noticed the mushy brakes have been kind of dangerous so I wanna bleed these this weekend. Does it matter what kind of suringe/oil I use? (oil im sure it matters, whats best?)


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## Curtis C (Mar 28, 2009)

Use dot 3 or dot 4. I have had best results forcing fluid in through the caliper and allowing to escape the lever. After putting the plug back in the lever you will get a couple of squirts out of the lever until the fluid level is equalized in the system. Just be ready to catch that excess fluid with a cloth.
Curtis


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## coop3422 (Jul 12, 2006)

ok, and does it matter what kind of suringe i use?


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## Curtis C (Mar 28, 2009)

I just grab some different size syringes from the pharmacy dept at Walmart. I would try to use a high volume syringe so you dont have to disconnect and refill. You need to be able to get a complete bleed with one fill.


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## wormvine (Oct 27, 2005)

coop3422 said:


> ok, and does it matter what kind of suringe i use?


Use DOT4. 
Use whatever syringe and tubing you want at the caliper but it would be best if you use the proper aluminum fitting for the master cylinder bleed port.

I usually connect the fitting to a tube that I run into a hole punched into the upper side of a 20oz plastic coke bottle that is hung from the handlebars with a piece of metal hangar wire. That way the extra fluid goes right into the catch bottle.

Here is what the fitting looks like:
http://www.spadout.com/p/hayes-hfx-9-bleed-fitting/


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## dogonfr (Jan 6, 2005)

These are the Strokers but the technique is the same except with syringe. :thumbsup:

http://forums.mtbr.com/showthread.php?t=415647


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## bommetje (Feb 18, 2012)

i thought i pushed the pistons back before bleeding the system (hayes 9 MAG).

Likely and hopefully i didnt do it right'.

After bleeding; my pads didn't fit on the caliper because the space was to narrow into the calliper to fit the pads.

can anyone tell me how to push the pistons back or whitch other problems i could have run in to?

I pushed the pistons back with a 10 mm.wrench as written in the hayes manual. (at least i tried)


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## bommetje (Feb 18, 2012)

some ciliconespray dit the trick and the pistons were back in place.

so, i rebleeded the system. when i was done, i tested the system and i saw the piston comming out, but didn't go back.

after 2 or 3 other attemps i pushed the piston out of its shell. All the liquid came out.

oooops

now what?


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## bommetje (Feb 18, 2012)

any tips here?


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## bommetje (Feb 18, 2012)

done!


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## IMT_trailrunner (Aug 6, 2011)

You can press the pistons back in by leveraging on them with a flat screwdriver... don't be a dolt and break ****.


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## sunvalleylaw (Jun 21, 2010)

Paul1977 said:


> Sounds like youve lost the plug from the master cylinder


ok, a back from dead thread. Tried to do this procedure with my son's older Trance and I think I broke the seal that holds the plug in. It came loose from the master cylinder with the plug. It does not seem to go back together that snugly without being connected like the other brake still is. I did not see anything about the plug being connected to the cap or I would have been more careful. Dang. Any suggestions?


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## sunvalleylaw (Jun 21, 2010)

Did some more reading and it sounds like I may have damaged the bladder or internals of the master cylinder, though it seemed at the time like a seal attached to the plug. Can anyone advise? Thanks. Need to get this fixed by Wednesday. May have to just bring it to the LBS as I may not have time to deal with it.


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## Rixington43 (Jul 1, 2016)

I know this thread is ancient and so are these brakes but I'm adding this post so it's searchable in case my experience helps anyone else out.
I recently started having issues with my trusty 9s which I've had over 15 years. The brakes would bleed fine and I could get all the air out but the pistons wouldn't float the pads to the caliper, they'd float one pull of the lever and then the lever would go to the bars.
After a ton of fluid, a fair bit of swearing and several hours I still had nothing. If I bled the brake without retracting the pistons though it was all fine and the lever was solid as a rock.
Long story short, check the tiny air hole on the master cylinder cap next to the bleed port plug, if this gets blocked then the baldder cannot move to take up the space of fluid going into the caliper as it develops a vacuum inside the master cylinder top cap. Clear the little air hole with a tiny needle and some aerosol brake cleaner (be careful not to go too deep and pierce the rubber bladder inside the master cylinder) and you'll fix the problem. You can check the air hole is functioning properly by applying a little soapy water (or spit) and then pulling the brake lever, you should blow a bubble.

Hope it helps someone, I now have my trusty 9s back, fingers crossed for another 15 years as I still love the old bruisers.


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## Mark 42 (Sep 16, 2015)

coop3422 said:


> bringing this back from the dead but my Nine's are really soft and my buddy just got a bike with Nines and his are super firm, which I want. And the past few rides I've noticed the mushy brakes have been kind of dangerous so I wanna bleed these this weekend. Does it matter what kind of suringe/oil I use? (oil im sure it matters, whats best?)


I just bought a bike with Hayes HPX-9 on the rear (the front has been swapped to Tektro). So, this thread isn't dead yet.


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## lightenup (Nov 1, 2008)

Mark 42 said:


> I just bought a bike with Hayes HPX-9 on the rear (the front has been swapped to Tektro). So, this thread isn't dead yet.
> 
> View attachment 1251612


Not even close to dead, I am going to bleed a pair of HFX9s tomorrow!


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## Dougal (Jan 23, 2004)

Mark 42 said:


> I just bought a bike with Hayes HPX-9 on the rear (the front has been swapped to Tektro). So, this thread isn't dead yet.
> 
> View attachment 1251612


You can still buy hoses, pads and pistons for these brakes. They've held up pretty well.


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