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murray mower, model unknown

I'm trying to take the brake off and the disc isnt budging. Tried hitting it pretty hard with a hammer, but wanted to check here before i really go to town on it.

first of all, isn't it supposed to just slide off? if so is there a better way to do it than smacking it with a hammer? here is a pic:


Thanks for any help!

http://i.imgur.com/yP7ZF1Q.jpg

shark, Hammers are a no-no unless soft. The picture looks like a "hub" not a brake disc. Stop hammering and tell us if you are serious, please. If this were a car a brake disc would slip over the hub . Where is the caliper or friction mechanism?

I already removed the caliper mechanism. This piece is what the two pads press against, there is a pad behind this one on the bottom.

It's the same thing that the guy takes off of his lawnmower in this video at 1:16

2003 Murray Widebody 42" Riding mower brake repair - YouTube

In that video he just slides it off, but mine is apparently stuck.

Beating on it will usually result in buying another transaxle or doing serious repair. Make a puller using 5/16" - 24 cap screws. If it is real stubborn, with some pressure on the cap screws, apply a little heat to the outer circumference of the rotor with a propane torch.

If the screws become loose it is moving. Apply no more heat than necessary but where the heat is applied is very important. On reassembly clean the splines, both internal and external, the best you can and apply Neverseize. Check and service semi-annually.

Shark, Apology, I looked at the video and I have not seen such a brake before. Senior's puller is great or you can buy a little "2 jaw" puller. Once the jaws are on the outside of the brake disc tighten the center puller screw a little and try gentle blow from a brass or lead hammer. The video looks like a seal might have leaked onto the spline of that unit so it practically fell off. Such a puller should not cost a lot. For a one shot or limited use try H Frt.

Edit. On second look one jaw may be a tight fit. If you decide on a puller don't be afraid to file or grind one jaw a little to sneak it under one side.

thanks guys.

senior - i like that idea, but i dont have screw holes on my disc... were those drilled out or something?

motoman - i think autozone has those 2 jaw pullers for rent so i might see if that works. i have to go there to get a fuel shutoff valve anyway because the carb keeps flooding the crankcase. im probably going to order a new seat/needle for it.

this is the first time ive worked on an engine and i completely tore it down and rebuilt it (had a broken rod)... the engine runs great now... i just need to fix the brake and carb and the mower will be good to go. a month ago i didnt know what a carb was haha.

Mine didn't have holes until I drilled and tapped them 5/16 fine thread. Knock off any burs from the rotor surface caused by drilling/tapping and you're good to go.

Being you're new to the mechanic world don't let this make you think you can't.

I would wonder about pushing with the bolts. Just what are you pushing against, the transmission case? be careful? I would say a puller and penetrating oil and if that doesn't work. A puller and heat.

reynoldston said:

I would wonder about pushing with the bolts. Just what are you pushing against, the transmission case? be careful? I would say a puller and penetrating oil and if that doesn't work. A puller and heat.

Click to expand...

No pressure on the case at all. Pushing against the shaft.

shark, Think again about an auto zone loaner. They may not take kindly to a mod to the one jaw (which you may have to make to grab the one side of the disc. You will end up buying it at AZ price. On H Frt they have a pitman arm puller, but the width is fixed $15. They have a 2 jaw gear puller same price which looks like you could mod. Finally, and without confusing you (I hope) H Frt has a "bearing puller" which may be just the tool for the little clearance showing in the pic of your disc. These are 2 pc thin pie plates that are made to slide under narrow spaces and then the 2 halves bolt together. You then can pull on the edges of this device with a 2 jaw . The pie plates also have threaded holes which can be used to created attachments for the puller $15.:thumbsup:


Edit, BTW shark good job on your first attempt.

Success! Ended up getting a 3 jaw puller from auto zone and it was a perfect fit for this thing... luckily there was enough space to get all 3 jaws behind it without modifying anything:

View attachment 23916

It wouldnt hardly budge at first, and i was cranking down on it pretty hard with a socket wrench. At one point i got some safety glasses cause i thought it was going to shatter. Backed everything off and sprayed pb all in it, as well as hit it a few times with a rubber hammer... also i took a propane torch to it for about 20 seconds all over.

Put everything back on and went at it again and it finally gave about 1/8th of an inch. Backed everything off and repeated the PB and torch. It kept giving a little at a time, and occasionally the whole assembly would start rotating, but a breaker bar in between the jaws fixed that:



Anyway, after about 15 minutes i got it all the way off and everything still looked in good shape:



Took another 10 minutes or so of dousing it with PB and working it back on and off the threads cause it was still extremely tight... but eventually i got it so i could take it off and on by hand.

And even better news, when i put it all back the brakes started working! Turns out those little studs in the caliper that push the pad were seized up... doused them with PB and kept pushing them in and out until they moved freely. That's the first time the brakes have worked since i bought it back in march haha.

Anyway, thanks for the help guys... you might see me in here some more. I really enjoyed rebuilding this and learning how everything works... from engine to electrical to brakes. I'm going to start telling my neighbors to bring their mowers over and i'll fix em just for fun, haha. Heck i even heard a rumor that you can make money doing this sort of stuff. !! :wink:

I use anti-seize to wipe over the caliper pins, & light coat on the shaft splines as well good preventive maintence.