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Forklift problems

First of all, let me apologize if this is off-topic. I did a search in google of previous threads about forklifts, and this group has a number of experienced people who have discussed them. That's the reason I post here. I just bought a used Hyster S60xl for use around my house. I tend to collect a lot of heavy junk! I don't know anything about forklifts though, and so this post is bit long because I don't know what's important for you to know. I was told the brakes were bad but everything else worked. I never even saw it, but it was so cheap....I had it delivered. The vaporizer/regulator (Impco model J) was apart when I got it, and after I reassembled it liquid propane shot into the mixer... After examining it, I realized there was a pin missing that controlled the valving of the liquid feed. I chucked up a nail in my old bridegport and made the missing pin from measurements I took from the vaporizer. Seemed like something .128 wide by .660 long would do the trick. Guess I did something right, it starts right up and runs excellent now. Now, to those brakes. The resevoir was empty. I assumed there was a busted line or leak somewhere. I added some DOT3 (is that's even correct) but it didn't leak as I expected. When I press the brake pedal, there's a liquid movement in the resevoir that suggests fluid is being pumped up into the resevoir. I see nothing happening when I release the brake pedal, but I assume it's sucking fluid back in. There are no air bubbles anywhere during this. Nothing is leaking, the ground is dry. If I press very hard on the pedal, sometimes it goes to the floor, sometimes it stops the truck. I was thinking I have air in the lines that needs to be bled, but I don't know why the resevoir would be dry in the first place if there was no leak. Hmmmmm.... So, how do I bleed these brakes? Is it like a car, bleeding at the wheel cylinders? Do I lift the truck up high to get under it, or pull the wheels off? Has anyone experienced just this kind of bad braking before? Maybe it's a bad 'pump' under the brake pedal? I'd appreciate anything that anyone can tell me about the brake system on these lifts. I'll be pulling it apart soon.....

Thanks, Jim

Reply to
Jim
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On Sat, 2 Oct 2004 15:25:55 -0700, Jim wrote (in message ):

Hydraulic brake systems are much the same in cars, forklifts, small aircraft, ect. From your description, my first guess would be the master cylinder piston is bypassing fluid and you need to replace or rebuild the master cylinder. I would also strongly suggest replacing all the brake fluid. The system can be bled from either the wheel cylinders or the master. Also recommend at least inspecting the wheel cylinders, linings ect.

Hope this helps.

Reply to
Roger Hull

I know little about forklifts... however I think one of the first things I'd do is find a factory shop manual for it.

Good Luck!

Erik

Reply to
Erik

It'd probably be worthwhile to see if you can locate a local dealer/service shop to see if they would copy a few pages of a service manual for your particular model.

Desirable bartering goods are donuts, pizza and various beverages.

I haven't torn into FT brakes for a long time, but they were just common split-opposed shoe pairs with a wheel cylinder. The shoes were considerably wider than typical car shoes. On the FTs I was servicing, the only clean spots on them were the seats. It's possible that any lost fluid would be absorbed by a thick layer of dirt, so it may not make it to the floor for quite a while.

Many brake fluid systems will gravity bleed to some extent if you keep the master cylinder filled, and you may be able to determine more after several days. My guess is that there would be bleeder screws for each front wheel.

WB .............

Reply to
Wild Bill

.

Cool. Not a piece that has real tight tolerances, fortunately.

Likely, but not gaurenteed. It should say either on the resivoir housing, or on the data plate (unless, of course, the plate is missing) Both of my shops lift trucks use DOT3 (the 8000Lb towmotor and the 25T Euclid)

I would bet on one or more of the following: the leak is at one of the cylinders and the fluid is ending up inside the brake drum on that wheel (very common, esp if water gets into the system), there is a line leak near a cylinder and there is still enough air in the system that fluid hasn't made it there yet, the master resivoir is leaking, or the fluid evaporated from neglect (DOT3 will vaporize, esp in warm climates). It may be as simple as a bleeder screw or line fitting that is loose. I have seen a ton of equipment with 'bad' breaks that ended up being a bleeder that was loose or had crud on the seat.

Don't bother lifting the machine. You may want to roll it onto a service rack, if you can. These are HEAVY units witht he weight way off center, and if you don't have the proper lift, it can be bad news. Even my little towmoter, with 2.5" ground clearance, can be bled without lifting it. One axle done from the top by removing engine cover and floor plate., the rears (steerign) by turning the wheels. Bleed untill fresh fluid at all points, like a car, farthest cylinders first. Personally, I would pull the wheels to check the linings and pistons on general principles, anyway.

Also, check the parking brake. Most likely a transmission brake. It is your best, most reliable friend. It will stop you and hold the machine quite well, at the expense of ease and control. Not meant to be a service break, and using it as one will wear it out quickly, but it is the final defense agaiinst service break loss. Practice with it, as stopping with it is a delicate process.

Reply to
e

I have to remove the front wheels (duals of course!) to bleed the brakes on my 10,000 lb hyster lift.

Shawn

Reply to
Shawn

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