Tony kart brakes boiling

Bruce Jackson · Posted: Tue Sep 11, 2012 1:28 pm Post subject: Tony kart brakes boiling

We had an issue this past weekend involving the brake fluid boiling during the LAKC Spec Honda race. The chassis is a 2011 Tony Kart EVRR shifter with 2 seasons on it. The brake system has worked flawlessly up until now with nothing more than pad replacments when needed. Any clues as to what the problem may be?
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Bruce Jackson

Steve Buckner · Joined: 22 Apr 2003 Posts: 839

Is it the fronts or rears or both. I would say dragging the brakes or pads to close to the rotor. If you top off the fluid and not leave a little room for heat expansion you could be pushing the pads out just enuff to slightly drag them.

The way the track was configured this past weekend you would have a lot less time for them to cool down.
Some tag drivers that switch to a shifter will trail brake a lot more than is needed.

John Matthews · Posted: Wed Sep 12, 2012 7:04 am Post subject:

You have to do more than just bleed the brakes periodically, you need to fully change out the fluid on a pretty regular basis. As brake fluid ages it absorbs water which will boil at a much lower temp than the fluid. Also, stay off the brakes. All they do is slow you down Laughing

Cheers,
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John Matthews
Heartbeat Power, LLC.

Bruce Jackson · Posted: Wed Sep 12, 2012 9:04 am Post subject:

Tim Doll · Posted: Wed Sep 12, 2012 9:17 am Post subject:

John Matthews · Posted: Wed Sep 12, 2012 1:41 pm Post subject:

Should be DOT 4 if it's like every other European chassis I've worked on. Minimum I'd use is Castrol GTLMA but I do like Motul 600 as well.

Cheers,
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John Matthews
Heartbeat Power, LLC.

Rich Hays · Posted: Wed Sep 12, 2012 2:11 pm Post subject:

The 2011 Tonykart uses DOT 5 brake fluid. Remove the mastercylinder resevior cap and see if the fluid is a purplish color (DOT 5).

-Rich

Mike Zamora · Joined: 26 Nov 2008 Posts: 56

John Matthews · Posted: Thu Sep 13, 2012 10:37 am Post subject:

Catching right up with MCP Wink

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John Matthews
Heartbeat Power, LLC.

Tim Doll · Posted: Thu Sep 13, 2012 2:38 pm Post subject:

OK, part of this isn't making sense...

If it's silicone based DOT 5, the whole reason to use it is that it doesn't absorb water and hence doesn't need to be regularly replaced (if you're going to regularly bleed the brakes, glycol DOT 4 is generally considered to be a superior brake fluid because it has better compressibility characteristics (silicon DOT 5 tends to hold small air bubbles which give a spongy pedal).

So if it's DOT 5 and doesn't absorb water, it wasn't old brake fluid that caused him to boil his brakes. Shocked

Tim
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Standard disclaimer - I'm FREE - No longer affiliated with any organization, I can say whatever I darn well please!.

Everett, Washington

Ryon Beachner · Advertiser Joined: 26 Mar 2007 Posts: 344

Bruce,

All Tony Kart systems have used DOT 5 brake fluid since the introduction of BS5 and BS6 in 2006. However many have mistaken it for DOT 4 as for a couple years, the fluid was an Amber color. Also, in the event that DOT4 and DOT5 are mixed, the entire system should be rebuilt in order to remove the jelly like substance that forms as a result of the mix.

It is good practice to rebuild both the calipers and the mastercylinders at least once a season. Over time the seals become distorted as a result of the heat and pad movement, and the calipers are typically the first to go. Even more so when the brake pads are run down an excessive amount, thereby allowing even more heat to transfer to the seals. Typically the number I throw out when someone is picky, is every 25 hours.

Although I would never recommend over filling the mastercylinders, it shouldn't effect the position of the brake pads in relation to the rotor as the reservoir will squirt any overfilled fluid out the cap when pressurized by the pedal movement.

If you need any help rebuilding, or need the parts, feel free to give me a call. I have every part for the system in stock and rebuild them routinely.
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www.2wildkarting.com
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John Matthews · Posted: Fri Sep 14, 2012 8:12 am Post subject:

+1 on the rebuilds.

It's one of the cheapest maintenance items on the kart and should be done whenever the brakes seem like they're not working properly. Also inspect everything really good because you can get hairline cracks, wear, or pitting that will cause problems without being obvious.

Cheers,
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John Matthews
Heartbeat Power, LLC.

Steve Buckner · Joined: 22 Apr 2003 Posts: 839

www.motorspot.com/motulin.html Read thru this.

Ryon Beachner · Advertiser Joined: 26 Mar 2007 Posts: 344

Steve Buckner · Joined: 22 Apr 2003 Posts: 839

I think you have the experience and have been racing Tony Karts for a while, so I am not questioning You. I just found it interesting where Motul made statements about the boiling point change. Didnt know if that is what Mr Jackson is dealing with. Motul on the other hand knows what they are selling and what is the best use of there product.

My 2003 Arrow brakes have never given me any problems in 9 years. But I guess you have to drive it for it to fail. Laughing

See ya at the track.