Some work done, but now the 1377 is much harder to pump

[JEBert]

I havent ever even seen a valve or spring

Pull them and take a look.  You have to take the trigger frame, barrel, and breech off, catch the transfer port, and pull the breech seal out of the valve for it to come out of the tube without damaging the seal.  The front trigger frame screw holds the valve in the tube.  Pretty much a complete tear-down as you will probably need to tap the valve out from the rear with a wooden dowel.  It's good experience to know just what's in there and how it works.
If I remember correctly, Mike has a good u-tube video of it.
Cheers,

[1377x]

watch crosshairs dissassembly video there are other videos on youtube that can give you a visual too

[breakfastchef]

The valve in a 1377 is pretty simple.

[Tater]

When I did the roll pin previously, I only pulled the piston out a little ways to lightly lube it. Would I still need to take everything apart like that?
I didn't adjust or do anything with the valve.

[1377x]

yes the tube has to stand alone to remove the valve

[Tater]

yes the tube has to stand alone to remove the valve

But you think I need to take out the valve, even though I never made any changes to it or even looked at it?

[1377x]

But you think I need to take out the valve, even though I never made any changes to it or even looked at it?

there could be debris in it causing the check valve to lock up.debris can be introduced into the systen in a variety of ways
there has to be something causing the problem dont you want to figure it out?
the only way to get to the bottom of this is to open it up give it a good cleaning then you will know everything has been checked over
or you can spend about $30-$50 to have someone else figure it out for you.then you might as well just get a new one instead of spending time and money having someone else look at it
if you was near me i would say bring it over and be ready to learn your gun inside and out by the time you left you could disassemble/reassemble it blind folded with one arm behind your back

[Tater]

there could be debris in it causing the check valve to lock up.debris can be introduced into the systen in a variety of ways
there has to be something causing the problem dont you want to figure it out?
the only way to get to the bottom of this is to open it up give it a good cleaning then you will know everything has been checked over
or you can spend about $30-$50 to have someone else figure it out for you.then you might as well just get a new one instead of spending time and money having someone else look at it
if you was near me i would say bring it over and be ready to learn your gun inside and out by the time you left you could disassemble/reassemble it blind folded with one arm behind your back

Hehe, I understand. I guess I'll just have to dive in. I'll probably wait for the weekend to start it since I'll have to do all the work on the kitchen table.
Thanks guys.

[PC77]

kitchen table gunsmith. Just dive into it you will do fine and learn a lot in the process. I have not taken one down yet but i would not hesitate to do it. If you get stuck the guys will help you out.
pc 

[WyoMan]

Tater - HTH, Go slow, keep everything clean, have a container handy for the parts, looks like there's people to help 

1377 Disassembly:
1.Remove pivot pin, barrel band, forearm, linkage, and piston
2.Remove right grip by removing screw 105-054 (this will help in removing screw 1322A029)
3.Remove grip frame by removing screw 1322A029 & 130B031 (careful here, the detent spring and ball, 1322-017 & 105-039 can fall out) I always (carefully) tip the grip frame upside down onto a towel and let them drop out. Then put into a small z-lock plastic bag.
4.Now that the grip frame is removed, the airtube, breech & barrel are easier to work on. Remove rear breech screw 1322-015. The rear sight, end cap 1322B002, and hammer spring 781A051 are free (hammer spring will have some tension when you remove this screw so keep one hand or finger on the end cap).
5.Remove the hammer by sliding to the rear and position where cocking pin 2100A011 is aligned with the removal hole. Pull pin and the hammer slides out the back of airtube.
6.Remove front breech screw 1322B027 (this is the infamous 4-48 that everyone strips at least once). Use a GOOD allen wrench and apply some down pressure on the breech (airtube should be on a flat nonskid surface). The breech and barrel are now free (careful here, the transfer port 1322A026 can go flying)
7.Remove transfer port seal 130-036 (a safety pin with a dull point works pretty good). You now have the airtube with only the valve to remove.
8.Get a 5/8" ( I think its 5/8") wooden dowel that is 15" long (longer ok). Locate the center on one end and drill a ¼" hole about 1" deep into the end. Look at the valve 1322C013 and the exhaust pin 760-145. The hole in the dowel is there so when you push the valve out of the tube with the dowel (from the rear to the front), the dowel will not push on the exhaust pin.
9.You're done unless you want to dive into the trigger group.
10.Reassemble in reverse order.
*Edit Loosen rear breech screw 1322-015 before removing grip frame screw 1322A029 (it will be easier)

[storsy]

Tater, when dismantling your pistol.
If you remove the complete trigger frame from the tube (before taking the side plate off), you shouldn't lose the safety ball, as it wont be under pressure and fly off.
A useful tip, i read on here.

[BDS]

Tater... here's a cool cut-away of the pistol to help you envision where you are going and what's there when you arrive! 

[1377x]

and heres a video to watch
this is your orientation
[youtube]https://www.youtube.com/watch?v=aLSnFP1hSEU#ws]Crosman 1377 disassembly[/url]

this one explains the valve and piston with mods
[youtube]https://www.youtube.com/watch?v=uIIG-aa3VrM#]Crosman 1377 piston and valve mods[/url]

[Tater]

Very cool diagrams guys. I've never seen them and I'm sure they will help. 

Edit: I hadn't seen the valve/piston video yet either. 

Looks like I have some homework to do.   

[1377x]

heres one more viseo to see.you know these videos are made by crosshairs

[youtube]https://www.youtube.com/watch?v=GUNpGingSxk#ws]Crosman 1377 frame disassembly[/url]