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Lull Telehandler brake booster problem

bill klein

New Member
Joined
Jul 18, 2020
Messages
3
Location
pa
My Lull brake booster often sticks so that the only brake fluid that returns from the 8 wheel cylinders is the volume of the master cylinder- not the booster cylinder. The result is that not all the wheel cylinders release therefore a brake hangs up. I have removed the extension from the booster and worked the rod by hand (sometimes I find it stuck out and a gentle bump makes it jump back in) and the brakes work well for a few dozen times then it goes back to sticking. Any ideas onwhat could be causing this? Bill Klein
 

Tenwheeler

Senior Member
Joined
Dec 15, 2016
Messages
870
Location
Georgia
Think I would be looking at the piston in the booster master cylinder. If the bore is not to bad maybe able to put a kit in it. Possibly just buy the cup seals from Napa. Parts maybe available from a local truck parts supplier or a reman from Bepco.
I have had great service from JLG but parts are high.
Look on line for a service manual. Some models have free PDF parts and service manuals.
 

bill klein

New Member
Joined
Jul 18, 2020
Messages
3
Location
pa
Thank you for the reply Tenwheeler. The booster cylinder was my 1st thought also but when I removed it from the front of the chamber the rod was still stuck out. I had to give the rod a bump before it retracted with a jump. Is there a shuttle spool or the like in the base that the cylinder extension screws in to? Bill Klein
 

tool_king

Senior Member
Joined
Mar 29, 2010
Messages
2,151
Location
new jersey
Occupation
road mechanic owner
Thank you for the reply Tenwheeler. The booster cylinder was my 1st thought also but when I removed it from the front of the chamber the rod was still stuck out. I had to give the rod a bump before it retracted with a jump. Is there a shuttle spool or the like in the base that the cylinder extension screws in to? Bill Klein
What model Lull do you have ? I can send you the manuals in pdf form .
 
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