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New member-4L80E problems

Rav

New Member
Messages
9
Likes
1
Location
Mississippi
Thread starter #1
I have a 2005 2500hd with transmission problems. It stopped pulling and showed P1810 code, so I replaced the tranmission fluid pressure switch and put new fluid in. It ran fine for maybe 30 miles then wouldn't pull again. If it sits for a day I can crank it and it will spin the tires, but after maybe a minute it stops pulling and has no power. If it sits again it will do the same thing. Does it in all gears and reverse. Help please.
 

Will L.

Well-Known Member
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Location
Boulder City Nv
#2
Maybe replacing the bad unit a loose electrical connection issue at the plug. Not a common issue, just possible.

Trying to remember but o ring damge on install possible?

Possible pinched, cut harness.

What brand part did you install?
 

Rav

New Member
Messages
9
Likes
1
Location
Mississippi
Thread starter #3
I Installed Standard Motor Products M14003 Transmission Pressure Switch Assembly. I checked all the plugs yesterday and still had the same issues. Before I installed the plug I had the same issues. The only thing we did was unplug the old pressure switch and put the new one in and put some fresh transmission fluid I. It and it ran like a champ for a day or so.
 

Rav

New Member
Messages
9
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1
Location
Mississippi
Thread starter #5
Good afternoon, I do not have transmission pressure gauge. If I buy one and find the pressure is low what would that indicate? The only code I am seeing is a knock sensor.
 

Rav

New Member
Messages
9
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1
Location
Mississippi
Thread starter #8
Any ideas on why it worked fine for a while after I put in the new pressure switch and new fluid? Then starting doing the same thing? Hate to redo tranmission and that is not the problem...
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
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ZEPHYRHILLS FL
Staff #9
The p1810 is a code that doesn't always limp immidiately. From what I found, it takes 2 drive cycles for it to go into protection mode C for that code.
 

Rav

New Member
Messages
9
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1
Location
Mississippi
Thread starter #10
I ordered the pressure gauge today. Can you tell me what pressure I am looking for? And is then when it is idle I test it or when? Thanks for all the help so far.
 
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Location
alaska
#12
Install 400 p.s.i gauge to pressure tap drivers side of unit. Check that oil is full and warm transmission up to operating temperatures. Warning: apply parking brake and foot brake during entire test!! With engine running shift transmission into drive with foot on the brake, at idle in drive, park and neutral the main pressure should be approximately 40-70 psi and with throttle depressed to floor should be approximately 160-180 p.s.i. only hold at full throttle 2 seconds or transmission damage may result! Reverse pressure should be approx. 60-70 p.s.i. at idle and approximately 300-330 psi full throttle. Again only 2 seconds! DO not repeatedly “brake stand the transmission” it will overheat quickly and do damage. You can have observer watch gauge in passengers seat while driving and should vary pressure with throttle smoothly. Do not drive and watch gauge at same time!!

What I found by googling
 

Rav

New Member
Messages
9
Likes
1
Location
Mississippi
Thread starter #14
I finally hook up the pressure gauge. Started I and It was around 40. When i put it into gear it went to zero and would not move. If I gave it some gas it would go creep up a little, but the pressure was very low and hardly registered. So is it rebuild time?
 

Rav

New Member
Messages
9
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1
Location
Mississippi
Thread starter #16
So would your next step be to buy a rebuild kit and start breaking it own and rebuilding it? Would the piston be included in the kit you think? Just want to make sure I am understanding. Thanks for all the help and insight. Ravi
 
Messages
5
Likes
9
Location
texas
#17
no the piston is not included in the kit but before you rebuild it look at the piston seal on it a friend of mine had a similar issue and come to find out the piston seal was torn
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
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Staff #18
I always tear down before I order parts. It could be a molded apply piston or just an accumulator piston seal blown out. The only way to know is to pull it down, and find it. Keep in mind you're not doing a basic rebuild, you're also doing failure analysis to find what failed, and to do your best it doesn't happen again.
 

Rav

New Member
Messages
9
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1
Location
Mississippi
Thread starter #19
I googled but am still a little confused. I have to drop transmission right and take apart to get to piston right? Are there more than one piston in transmission. Sorry for newbie questions.
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
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Staff #20
Yes, there are numerous pistons inside of a 4l80e. Don't take this the wrong way, but it sounds like you are in WAY over your head here. The 4l80e is not a very complicated automatic transmission, but it is also not one that you want to learn how it works by rebuilding it. I strongly reccomend you take this to somebody and let them diagnose and repair it for you. Paying somebody to start with to fix it will most likely be cheaper than you doing it a couple of times then taking it to somebody to fix it. With an auto transmission you can easily cause more damage to it by not knowing what you're doing, than is wrong with it to begin with.
 
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