B7510 HST won't start

[rbcsaver]

For sometime, my 5 yr old B7510 HST would continue to move slowly forward when pressure was taken off of the pedal, and often would have to tap the reverse pedal to stop it. Sometimes, the tractor would not start until the pedal was re-centered. This happened yesterday and again I tried to exam the pedal linkage cluster under the deck.

For the first time, I noticed the Zerk fitting on the HST pedal housing and greased it. I also sprayed some Blaster lubricant on the other linkage parts. No the tractor sits in the same spot because it wont start. Turn the key and "click" is the only sound. PTO is off.

The forward HST pedal now seems to sink to the deck and the reverse pedal is higher. In addition the inherent pedal friction seems to be absent. I checked the fuses and they all appear OK. I have not yet jumpered the seat shutoff switches, but will try that after I leave this note.

I ordered a shop manual, but that won't get here for 2 weeks. It's very difficult to see and understand how that linkage works. I called a local dealer, but he was of little help and no ideas.

Any suggestions?
Regards,
Steve

Addendum,
Bttery, fuses are all fine. There must be a cut off switch for non-centered HST Pedal, because it won't start if not centered, but I don't know where it is.
I tried jumpering the under seat switches but to no avail. I don't see a "V notched plate." When it stops raining, I'll post a picture of the cluster.

Here's an update,
I took the right rear wheel off and can see where the rod that comes through the bracket, doesn't anymore. Thus the cut off switch is in the open position. I managed to remove the pedal return spring or shock. I can't tell which because it's covered in corrugated rubber and now the pedal had no resistance at all. But there is so much brake linkage and stuff that I can't see how the rod even connects to and is activated by the linkage. Anyone have knowledge or diagrams?
Thanks,
Steve

 

[Egon]

How is the battery and all the connections?

Is there cut off switch for centering the HST pedals as well as checking all the cutoff switches?

Does your tractor have a wheel that centers on a v notched plate? If so make sure the wheel is properly on the plate and everything moves freely. It may also have a spring which can be tightened to provide more force to center the pedals???

 

[lawn_king]

Every now and then my B7500 would refuse to start, i would have to connect the posts on the starter with a screwdriver ( PITA ), i never did find the problem?

 

[dex3361]

Go to this link the index of Kubota books
Index of Kubotabooks/Tractor Parts Manuals/

It is a PDF of the parts manual and it has exploded views and this may help you sort out the issue.

 

[Volfandt]

Some, not all of the smaller B models seems to have this problem. Some have replaced all the safety switches, recrimped the wireing connections and replaced the battery to no avail. Altho any of those previously mentioned fixes can be your problem.
Kubota came out with a relay kit that fixes the problem when all else fails.
Basically the combined resistance of the wireing and safety switches drops the current to a point where it's not sufficiant to pull in the starter solenoid's plunger to engage the starter, hense the click.
The "fix" is to wire a low current 12vdc relay into the safety switch/starter circuit and use it's high current normally open contacts (at least 15 amps DC) to energize the starter solenoid. (it takes less current to energize a relay as opposed to a high current handleing solenoid).
If you don't feel comfortable in fab'ing up this circuit, check w/a Kubota dealer for the kit.
Good luck

just read your addendum.
1st thing to do is have someone work the pedals while you watch the linkages around that switch. Sounds like it's the HST pedal safety switch you've pictured. It's probably a normally open switch that closes the contacts when depressed. You should be able to temporarily shunt/jumper it out for testing, and then figure out whats missing and/or mis-adjusted on the linkages.

 

[Firefighter Kubota]

My 7510 did the same thing,, Ist it was the seat switch..I bypassed that one! even though there are some convinced that I will now get run over...

And my HST pedal wasn't completely aligned the the safety switch, there is an adjustment on the rear of the switch mech.. It's been a while so I don't remember the details completely... Service should be able to tell you over the phone!!!

Good luck

 

[rbcsaver]

I have to go out now and try and get part of the deck off etc. It is NOT the cut off switch. I pushed the contact in with a screw driver and my wife could turn it over.
Look at the first pic I posted above. The rod that comes from the pedal assembly has either broken or come out of the top of the pedal. I hope it's just a broken cotter pin,
but can't see or get in there behind the brake linkage. I did remove a part called the "HST Damper" which my also be bad, but that's a spring or gas shock like part.

That's another reason to buy a tractor with a left sided brake!
more later.
Steve

 

[Egon]

I don't see a "V notched plate."

That will not apply for your tractor.

After looking at the diagrams your tractor linkage assemble is much different than the one I had.

 

[rbcsaver]

It comes down to something in the "Neutral Holder Link" mechanism being broken. It appears that I can **temporarily** bypass the switch for now and get the tractor to run, since it's stuck in the driveway with mowing deck and FEL in down position. He explained that it's a safety mechanism so that it the tractor is NOT in neutral and you get off it stops moving.

Problem is I don't see any access, but the tech says you get to it from underneath.
I really need this on my Vacation, while trying to get things done.

 

[Egon]

Will taking a tire off help for access?

Can you remove the mower?