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Desperately need help ! These brakes are doing my absolute head in ! They needed to be bled so with the brake bleeding tool the left hand side bleeds are perfectly no dramas at all ! The other side just isn't happening for me at all ! Something is massively wrong here as I can't even get fluid to come out of the bleed nipple on that side ! The pad was even moving out when brake pedal pumped but it wouldn't retract back in place ! When I removed the calliper away from the brake disc the pad just kept coming out and out and out with every brake pump but wouldn't go back ! I pulled everything apart cleaned it and put it back together tried bleeding them up again the good side works perfectly again and the bad side won't even bleed up or move at all now ! After 3hrs trackside at Todd Road after driving down from Albury I threw the towel in (after throwing nearly every tool in my tool box across the car park) could it be a seal or something that's gone ??? I've never had an issue bleeding them before today

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Kane, the procedure I use is outlined below and I have found it to work well - this of course assumes all parts are in good condition.

Things to check - a blockage in the system, the pushrods are free (see no. 13 below), or a piston seal has dislodged. Also note no. 14 below.

Regards,
Pete

BRAKE BLEED PROCEDURE:
1. First make sure that both master cylinder pistons are fully returned as far as the retaining circlips.
2. Fit the bleed tower but leave the tap on the tower closed.
3. Fill the bottle with dot 5 fluid or 5.1 depending on year model / preference
4. Remove the reservoir cap on the cylinder you are connected to.
use a rag to soak out all of the fluid in the reservoir
6. Now open the tap and allow the reservoir to self fill until 1/3 full only then close the tap.
(if the reservoir does not fill when the tower tap is open the piston is not fully returned and the cylinder will need cleaning and checking)
7. Now re fit the cap & seal with the reservoir only 1/3 full.
8. Now open the bleed nipple on the caliper.
9. Next open the tower cap and allow the fluid to flow until clear of bubbles then close bleed nipple.
10. Close the tower tap and remove.
11. Re fit the cylinder plug ensuring the rubber seal is in good condition.
12. Repeat the the process for the other cylinder and you are done.
13. Just check that when your brake is set up the two push rods on the balance bar are totally free of the master cylinder pistons. any pressure from these rods on the pistons will cause brakes to drag when hot.
14. Another cause of brake drag and eventual overheat is having the fluid reservoirs more than 1/3 full.
When correctly bled the pedal should be firm and the balance bar should be square and even when under pedal pressure.
Thanks so much for the reply Pete I will definitely give this a go and let you know how it all goes

Peter Hudson said:
Kane, the procedure I use is outlined below and I have found it to work well - this of course assumes all parts are in good condition.

Things to check - a blockage in the system, the pushrods are free (see no. 13 below), or a piston seal has dislodged. Also note no. 14 below.

Regards,
Pete

BRAKE BLEED PROCEDURE:
1. First make sure that both master cylinder pistons are fully returned as far as the retaining circlips.
2. Fit the bleed tower but leave the tap on the tower closed.
3. Fill the bottle with dot 5 fluid or 5.1 depending on year model / preference
4. Remove the reservoir cap on the cylinder you are connected to.
use a rag to soak out all of the fluid in the reservoir
6. Now open the tap and allow the reservoir to self fill until 1/3 full only then close the tap.
(if the reservoir does not fill when the tower tap is open the piston is not fully returned and the cylinder will need cleaning and checking)
7. Now re fit the cap & seal with the reservoir only 1/3 full.
8. Now open the bleed nipple on the caliper.
9. Next open the tower cap and allow the fluid to flow until clear of bubbles then close bleed nipple.
10. Close the tower tap and remove.
11. Re fit the cylinder plug ensuring the rubber seal is in good condition.
12. Repeat the the process for the other cylinder and you are done.
13. Just check that when your brake is set up the two push rods on the balance bar are totally free of the master cylinder pistons. any pressure from these rods on the pistons will cause brakes to drag when hot.
14. Another cause of brake drag and eventual overheat is having the fluid reservoirs more than 1/3 full.
When correctly bled the pedal should be firm and the balance bar should be square and even when under pedal pressure.
Yeah maybe time for a rebuild with new seals....also check the bleed nipple hasnt crushed. OTK bleed nipples easily crush and close up if over torqued or over used....

My Dad and i had the same issue as you with an OTK Kosmic Kart, the brakes were soft, one side pushed more in than the other and they weren't retracting as they should, we took the brakes apart, cleaned it out, new fluid and nothing had changed, in fact it had gotten worse. we sent the kart to Melbourne kart center and was told the seals were gone and that they couldn't exactly put their finger on in but was told that particular components of the brakes weren't as tight as they should be, Just got the kart back with new seals a day ago and felt the brakes on the stand, feel good but haven't taken it out yet, guess ill find out at Portland this week end XD best of luck!

So checked the bleed nipple it looks terrible on the end of it and so does the end of the hole it goes in to ! It's all chewed out looking must have been over tightened at some stage

Craig Westwood said:
Yeah maybe time for a rebuild with new seals....also check the bleed nipple hasnt crushed. OTK bleed nipples easily crush and close up if over torqued or over used....
Good luck this weekend and yeah hopefully I'll get to the bottom of it sounds like I'll have to rebuild the brakes like yourself

Nikola schmidt said:

My Dad and i had the same issue as you with an OTK Kosmic Kart, the brakes were soft, one side pushed more in than the other and they weren't retracting as they should, we took the brakes apart, cleaned it out, new fluid and nothing had changed, in fact it had gotten worse. we sent the kart to Melbourne kart center and was told the seals were gone and that they couldn't exactly put their finger on in but was told that particular components of the brakes weren't as tight as they should be, Just got the kart back with new seals a day ago and felt the brakes on the stand, feel good but haven't taken it out yet, guess ill find out at Portland this week end XD best of luck!

we were considering buying an after market set but we thought we'd try the rebuild first, Thanks!

Kane Richards said:

Good luck this weekend and yeah hopefully I'll get to the bottom of it sounds like I'll have to rebuild the brakes like yourself

Nikola schmidt said:

My Dad and i had the same issue as you with an OTK Kosmic Kart, the brakes were soft, one side pushed more in than the other and they weren't retracting as they should, we took the brakes apart, cleaned it out, new fluid and nothing had changed, in fact it had gotten worse. we sent the kart to Melbourne kart center and was told the seals were gone and that they couldn't exactly put their finger on in but was told that particular components of the brakes weren't as tight as they should be, Just got the kart back with new seals a day ago and felt the brakes on the stand, feel good but haven't taken it out yet, guess ill find out at Portland this week end XD best of luck!

OTK Brakes? .............. well the set I have is obviously the same as you have.

Now Ask an Ausy dealer for SOFTER PADS, and I was told that OTK do not make them.

However on EBAY, out of UK .................. SOFTER OTK PADS!!!!!

Made a hell of a difference

But you need to have everything else all good and going for you..

Max.,

Thanks for all the ideas last week fellas ! To follow up I ended up tidying up the hole where the nipple goes in and drilled a hole through where the end of the nipple had broken off in there ! Replaced both nipples then followed Petter's bleeding instructions and they're working a treat now !

Kane, good work!

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