.20 Cal Sheridan Blue streak (1974)resealed and new pump cup and still won’t pump up!

[Adrian Garcia]

Hello Cool Cats,
I just recently was able to get my hands on 5 Blue Streak (1974) .20 cal Sheridans.

I took 1 apart to start- cleaned out everything (old lead washers etc.) replaced with new kit including pump cup, and it still won’t pump up.
Tried Alcohol Flush also.

Frustrated because I’ve tried everything I can find info on and still not building air.
I used the original multiport valve body.
Could this be the problem?
Please HELP!!!
AG

 

[Hobbyman2007]

Are you cocking the rifle before pumping ? If not that might help it to seal.

 

[Adrian Garcia]

Good morning!
Yes-I tried cocking before pumping, didn’t work.
The white check valve (round plastic disc) that comes in the kit, it has a slight taper to it. Does it go in a certain way?

 

[Frank in Fairfield]

Yes

 

[Adrian Garcia]

Taper to the spring side-I would assume?

 

[jarmstrong]

6 min 20 sec mark

 

[DonR]

Adrian, you haven't mentioned whether you're able to build pressure but it leaks out fast, or whether no pressure is created. A few notes:
> If you feel no resistance when pumping, something is not right with the pump cup.
> If you feel resistance but the pump handle is forced all the way open after pumping, it's a check valve issue.
> If you hear air hissing out the barrel, it's an exhaust valve issue.
> The original valve body is fine, assuming you cleaned it up for re-use.
One item sometimes overlooked, is the need to polish both the brass intake and exhaust valve seats. Any nick on their surface can cause leakage. Emery paper on the end of a dowel will work for the inlet seat far down inside the innards.

Tell us more about your specific symptoms, which can lead to ideas for diagnoses.

Don R.

 

[Adrian Garcia]

Hello Don,
I changed the first New Pump Cup that I had installed (very soft-brand new) with another brand new (hard) pump cup!
*(Different suppliers)
Felt resistance right away!
8-pumps 675 fps-WOW!!!
Thank you Sir!,
~Adrian