Lph-400 needle sticking.

CK-2

Promoted Users
I went to spray some sealer tonight with my lph 400 and the trigger was hard to pull and wouldn’t return to seat.
I just used the gun a week ago and everything was fine.
So I pulled the needle out and unscrewed the packing nut. Holding both pieces in my hand the needle is really hard to push through the nut. The rubber in the nut feels really hard. I tried some Vaseline but it didn’t help.
I figure the packing nut is my problem? Can these things go bad that quick from one week to the next?
I have a tailgate ready to spray and hate to wait a week on parts. What else can I do?
 
Last edited:
Normally, they never go bad. The only time I've seen the needle stick is because the packing nut is too tight. Try some spray gun lube on the needle where it goes through the nut, then tighten the nut until you feel the needle start to get tight, then back off a little. If this doesn't work, you will have to replace the gasket.
 
I’ve had this gun for about 16 years. I’ve had to tighten the nut and loosen the nut over the years. But it’s tight now just holding the nut and needle in my hand.
Was afraid of oil just due to contaminating a paint job. But it’s not going to work the way it is.
Does the rubber separate from the nut or is it all made together? Mines stuck together tight.
 
Well, I didn't actually mean they never went bad, lol. After 16 years it's due for a kit just from age, especially if it sits a lot. The spray gun lube won't contaminate your paint job, it's a specialty product made for this purpose. You should be able to get a kit at your local jobber.
 
Last edited:
I think the lube, the one I use is a grease like substance, should do the job. I have had mine for years now and if I don't take it apart and clean everything once in a while it will stick. Normally, I rinse out the cup, soak the tip set and wipe everything down but a thorough cleaning is needed every few years. LOL
 
I think the lube, the one I use is a grease like substance, should do the job. I have had mine for years now and if I don't take it apart and clean everything once in a while it will stick. Normally, I rinse out the cup, soak the tip set and wipe everything down but a thorough cleaning is needed every few years. LOL
I use and really love aerosol gun cleaners. It really blasts the nooks clean.
 
i have never replace the packing . my guess is it is either dirty or has been over tightened . i would clean it well ( never let it soak ) then roll it on a hard surface . when you reinstall it do not tighten much past finger tight . little gun lube will help .
 
i have 2 lph400's that are 15+ years old. never changed the needle packing. only time the needle sticks is when it needle gets paint buildup on it. just a cleaning of the needle usually works. if the packing is built up with paint that could also be a problem. if you dont have gun stripper then toss the whole thing in a cup with lacquer thinner. its a teflon piece so it wont hurt it. just let it sit for 15-20 min then clean it out with some fine needle brushes from a gun cleaning kit.
 
Thanks everyone for the advice. I ordered a new packing today, I’m supposed to have it tomorrow.
I never tighten it very tight and I remove my needle and clean each time I spray. I removed the packing nut and let it soak in laquer thinner last night, it’s still the same today. I tried cleaning with small brushes etc with no luck. As I said earlier it’s hard to push the needle in with the packing nut out of the gun and in my hand. The rubber part is really hard.
It’s 16 years old and never gave me a problem, but something has happened since last weekend. Hopefully the new one will solve my problem.
 
Interestingly enough, I had the same problem today. Pulled the needle and it was clean, but I buffed it with some steel wool in case my old eyes were missing something. Sprayed some carb spray through the Teflon packing and used a tiny brush to scrub it out. Put it back together and it works like a champ. I remember the old packings before Teflon, they were some kind of gasket material, now those definitely needed oil and regular adjustment!
 
Last edited:
Thanks everyone for the advice. I ordered a new packing today, I’m supposed to have it tomorrow.
I never tighten it very tight and I remove my needle and clean each time I spray. I removed the packing nut and let it soak in laquer thinner last night, it’s still the same today. I tried cleaning with small brushes etc with no luck. As I said earlier it’s hard to push the needle in with the packing nut out of the gun and in my hand. The rubber part is really hard.
It’s 16 years old and never gave me a problem, but something has happened since last weekend. Hopefully the new one will solve my problem.
My kids never gave me trouble until they turned 16 years old. Must be the magical age.
 
Got my rebuild kit today. The new packing nut is totally different from my old one. The old one is black rubber.
New one works slick.
 
Back
Top