K-sport hand brake issues

So I bought a cheap K-sport hydraulic hand brake. I installed it, plumbed the lines, bleed it and it works....just not perfect. You step on the brake pedal and the rear brakes work fine. You pull the handle and the tires lock up fairly easily. But if you push the brake pedal and then pull the handle then let off the foot pedal and then the lever, the rear calipers don't release all the way and drag quite a bit. At this point you can notice that the hand brake lever is stiffer than it usually is. They continue to drag until you reapply pressure to the foot pedal at which point you hear a slight click (may or may not just be the brake light switch) and the system then operates normally. I have a wilwood proportioning valve between the main master and the handbrake master and have not ruled out that this isn't what is causing the issue. I emailed k-sport and they didn't seem to know what was going on and suggested I had air in the lines and that rebleeding them would solve all of my problems. I don't think that sounds right.

I've read other places and on this forum that the k-sport master is just a pile of crap and that a wilwood will solve all of my problems. I also saw one spot where someone said the wilwood caliper did the exact same thing as the k-sport. I'd like to just buy a wilwood and be done with it but I don't want to buy it and have the same problem. Can anyone tell me whether or not the wilwood will act the same way or not? Could it possibly be air? Proportioning valve?

I assumed they all did this. Im running a willwood and it does the same thing. I havent found it to be an issue in real life situations. Just playing in the garage. I have no proportioning valve so its not that.

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First rally 2013
Rally car type AWD subaru
Total rallies as driver 6
Total rally cars built 2
Total rally cars caged 3
Total rally cars repaired from offs 4
Total years racing exp other then rally 19 yrs
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Don't do it in that order then. Handbrake is for oh shit moments, not for regular use.

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Grant Hughes

Quote
Reamer
I assumed they all did this. Im running a willwood and it does the same thing. I havent found it to be an issue in real life situations. Just playing in the garage. I have no proportioning valve so its not that.

I guess they do and I just didn't realize it. It looks like the professional solution to the problem is one of these:

http://www.gieffesrl.it/ENG/fcard/braking/master_cylinders_and_accessories/fittings_and_accessories/scheda/shuttle_valve.html

or

http://www.kollevold.no/bremser/handbrekk/fordelingsventil-hydr-handbrekk-detail

Now to find the grassroots solution. haha.

I use the CNC Turning brake, never had an issue with that.

Quote
phlat65
I use the CNC Turning brake, never had an issue with that.

But did you push it in exactly that order to see if it would do it...
It sounds like a nit pick to me.
You have to brake, handbrake, release foot, releast hand, then it drags until you foot brake again. Sounds like a situation that would never occur during racing and easily fixed by pushing foot brake again?

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Grant Hughes

It sounds like the handbrake is adjusted too tight and the seal is keeping the transfer port covered, preventing fluid return.

I'm assuming that the unit has a backstop for the lever instead of just allowing the handbrake master to go to the end of its travel.

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Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

I have done that Grant, and it did not drag the rear calipers.

I have a willwood with no back stop. If the seal is covering the transfer hole then its willwoods problem. It really is no big deal to me. Not sure how a cnc is any different to not have this happen? There piped the same way in out?

Like i say I thought this was part of having a hand brake piped in line with the foot brake. If there is an easy fix I guess I would fix it.

I know the travel on my hand brake is more if I dont use the foot brake. I have found at times when playing around that if I hit the foot brake then the hand brake the hand brake is right at the top of travel. Assumed this was from the fluid the foot brake put into the hand brake.

I am running a tilton pedal box maybe they feed/return different then a stock master?

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First rally 2013
Rally car type AWD subaru
Total rallies as driver 6
Total rally cars built 2
Total rally cars caged 3
Total rally cars repaired from offs 4
Total years racing exp other then rally 19 yrs
Like 31motorsports on FB!
Check out 31motor sales on ebay for used Subaru parts

Everybody that buys ksport junk has problems, so WTF!

Its obvious that the mc has the "blue printing" of the pressure, feed, and bleed holes done by eye, a Chinese eye of all things! Bite the bullet and buy a new master, wildwood or girling will look exactly the same as that one.

Mine is not a k sport and like I said it is a willwood master. Big writing on the side saying willwood!

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First rally 2013
Rally car type AWD subaru
Total rallies as driver 6
Total rally cars built 2
Total rally cars caged 3
Total rally cars repaired from offs 4
Total years racing exp other then rally 19 yrs
Like 31motorsports on FB!
Check out 31motor sales on ebay for used Subaru parts

Quote
Reamer
Mine is not a k sport and like I said it is a willwood master. Big writing on the side saying willwood!

well even Tiltons and APs sometimes need to be reshimmed. Either way they piston bellow is not uncovering the breather hole completely for the retraction. Could be the master housing or the rod thread out too much and slightly pushing on the piston. Test is on bench with some air pressure.

So the hand brake works fine with normal use. The breather hole is made by a chinese guy. When you do the wrong sequince the chinese guy hops on the missing plane flys to my garage and moves the hole so the piston bellow will cover the breather hole?

Or does the fluid put in the hand brake from the foot brake hydrolic the piston from returning? Or does the fluid from the foot brake not allow the piston to clear the breather hole? This issue is not a big deal. a quick tap of brake and it releases. I am curious now why it locks up. I cant visually picture what is happening? The handle is full return in both cases.

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First rally 2013
Rally car type AWD subaru
Total rallies as driver 6
Total rally cars built 2
Total rally cars caged 3
Total rally cars repaired from offs 4
Total years racing exp other then rally 19 yrs
Like 31motorsports on FB!
Check out 31motor sales on ebay for used Subaru parts

probably the difference on the way the inlet and outlet ports are between diferent master cylinders

here is a thred with a comparison
http://forums.bimmerforums.com/forum/showthread.php?1921948-Hydro-Ebrake-sticking/page2

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lawrence knox aka fidel
knox motorspors
knoxmotorsports.us

That bmw thread was the one place I saw where one of the guys switched to a Wilwood master and said he still had problems. Maybe he switched to a non Girling one, I don't know. And now Jeff is saying he has a problem with his wilwood.

Jeff, is yours a Girling style?

I'm not convinced a new master will help. It seems like this should be easier to figure out than it is. Like that guy in the bmw thread never posted back if switching ever helped. I found a diagram on an old thread here that showed this photo.



That little round thing connecting the two lines after the handbrake is a shuttle/priority valve. I was thinking this was how it had to be done but I don't really know.

Here is the wilwood master I was looking at. [url=http://www.wilwood.com/MasterCylinders/MasterCylinderList.aspx?group=Compact Remote Reservoir Master Cylinder]master cylinder[/url] It says Girling.

Paulinho, are you saying your 100% sure this master cylinder with solve my issues?