First Post - Having problems with my hydraulic caliper

[wyshadow]

I've been working on this Yerf Dog several months and I'm almost done. The only thing I have left is getting the brakes to work. The master cylinder, brake hose, and caliper are new. No matter how hard I push on the brake lever, the caliper doesn't put enough pressure on the disc rotor. I used a Harbor Freight vacuum bleeder and used the empty container method, and I'm sure there is no air in the system. I have read similar problems to what I have on vehicle forums and wanted to know if my problem might be a loop I have in the brake hose?

 

[Karttekk]

Are the brake pads adjusted up as close to the rotor as possible without excessive drag? Usually when a brake hose goes bad it won't let the fluid back into the master and the brakes drag and smoke. Try readjusting the pads. Scuff the rotor with #60 or #80 grit sandpaper to knock of any glazing then rinse with Brakleen.

 

[wyshadow]

Karttekk,
How do you adjust the brake pads? When I push on the brake pedal, I can see the brake pads move but not enough movement to stop the go kart.

 

[Karttekk]

There should be an adjustment bolt or screw with a locknut on it in the caliper. Loosen the locknut then turn the adjustment "bolt" in until a pad or pads touch the rotor with slight drag. Tighten the locknut. It's easier if you put the rear of the kart on stands in order to turn the rear wheels while you do the adjustment.

Here's an image.

 

[wyshadow]

Karttekk,
The brake caliper I have doesn't have an adjustment bolt. I just got off the phone with a mechanic and from what I describe to him, he thinks I might still have air in the master cylinder. I never bled a master cylinder before and is this normal to do for a go kart?

 

[Karttekk]

Once you open up a hydraulic brake system it will need bled no matter what vehicle. There are sealed one piece systems available depending on the kart.

https://hammerheadperformance.com/brake-kit-for-mudhead-80t-6-000-305-kit

 

[wyshadow]

The mobile mechanic got the brakes working. The problems were two things.
One was this clip inside the caliper. The clip was keeping the brake pads from moving.

The other problem was the brake caliper mounting bracket. The mechanic had to grind off a fraction of an inch so the brake pads didn't bind up.

 

[Karttekk]

Thanks for sharing the solution. For whatever reason I can't view the photos. Glad you got it going.

 

[wyshadow]

Karttekk,
Didn't have a problem getting the kart to go but getting it to stop was the problem. Just joking with you. I took my daughter around the neighborhood for a test drive and this kart vibrates so bad at certain speeds. The vibration actually loosed a couple of lock rings on the axle. It doesn't vibrate at a slow crawl but vibrates about 10-15 mph but then goes away at faster speeds. Not sure what I'll do about the vibration.

 

[Karttekk]

What I meant by "getting it going" was I'm glad you figured out the problem. As far as vibration, I would put the kart on stands and run it. Check the wheel and axle bearings, check the chain for binding links, make sure the engine is secure and not vibrating against the frame or seat, see if you have a tire that's out of round, check the disc brake rotor for excessive runout (warped) or a slightly bent axle.

 

[mckutzy]

What is the motor???

 

[wyshadow]

What is the motor???

predator 212

 

[mckutzy]

I have found out there is a range where it vibrates alot.. at higher speeds, it settles down...
These motors are inherently imbalanced.
It's kinda the nature of the Beast...

 

[wyshadow]

I had the mechanic come back yesterday again. After riding around the go kart, I've noticed the braking is not strong enough. The mechanic suggested installing bigger rotors than the 8 inch ones I have on now. I don't want to go back and re-position the the caliper for bigger ones. I'm thinking of installing another brake on the axle so that I'll have dual brakes for the rear. The problem I'm having is which master cylinder will work for this? I've been looking at this master cyclinder
https://www.bmikarts.com/MCP-Billet-Alum-Master-Cylinder-78-Bore_p_10452.html
Will this one work?

 

[wyshadow]

I ordered two sets of 8 inch rotors from Go Power Sports and installed one of them. The braking issues I was having is out the door with the rear wheels locking up with no problems. As you can see in the pictures, the thickness of the new rotor in noticeable. I was about to order a hold new three disk braking system if this wasn't going to work but now I don't have to this.

 

[landuse]

I ordered two sets of 8 inch rotors from Go Power Sports and installed one of them. The braking issues I was having is out the door with the rear wheels locking up with no problems. As you can see in the pictures, the thickness of the new rotor in noticeable. I was about to order a hold new three disk braking system if this wasn't going to work but now I don't have to this.
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View attachment 121424

Nice!!!