700R4 rebuild question
Thread Starter
Racer
Joined: Jul 2013
Posts: 294
Likes: 10
From: Palmer Alaska
700R4 rebuild question
late 87 700R4. When pressure testing input drum the checkball leaks a bit. Is this ok? Should it be zero leak? I tried cleaning with carb cleaner. Maybe seat it with a drift and hammer?
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
What do you mean by "leaks a bit"? And how much pressure are you applying to it? I don't think any 'ball-and-tapered hole' check valve will completely seal, if significant pressure is applied.
If you are not applying much pressure and it is leaking a lot, you need to inspect the seat for damage or excessive wear.
If you are not applying much pressure and it is leaking a lot, you need to inspect the seat for damage or excessive wear.
Thread Starter
Racer
Joined: Jul 2013
Posts: 294
Likes: 10
From: Palmer Alaska
What do you mean by "leaks a bit"? And how much pressure are you applying to it? I don't think any 'ball-and-tapered hole' check valve will completely seal, if significant pressure is applied.
If you are not applying much pressure and it is leaking a lot, you need to inspect the seat for damage or excessive wear.
If you are not applying much pressure and it is leaking a lot, you need to inspect the seat for damage or excessive wear.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,116
From: Crossville TN
If you are using air for the test, that's a completely different 'animal'.
The conversion factor for leakage using compressed air, rather than oil, is approximately 7:1. Since you are using 40 psi, that would be the equivalent of applying 280psi of oil for that leak test. The volume of air escaping to atmosphere (assuming normal atmospheric pressure) is representative of that same volume of oil escaping.
I suggest that you lower the pressure to 20 psi. If the leakage is a gentle flow of air from the check valve, it's likely fine to reuse. If it has much force to the flow 3-4 inches away from the outlet, you may have a problem.
P.S. I do not have any specified value for leakage from that check valve. But it will leak some. You might back-flush that check valve to see if there is any debris retained in it.
The conversion factor for leakage using compressed air, rather than oil, is approximately 7:1. Since you are using 40 psi, that would be the equivalent of applying 280psi of oil for that leak test. The volume of air escaping to atmosphere (assuming normal atmospheric pressure) is representative of that same volume of oil escaping.
I suggest that you lower the pressure to 20 psi. If the leakage is a gentle flow of air from the check valve, it's likely fine to reuse. If it has much force to the flow 3-4 inches away from the outlet, you may have a problem.
P.S. I do not have any specified value for leakage from that check valve. But it will leak some. You might back-flush that check valve to see if there is any debris retained in it.
Thread Starter
Racer
Joined: Jul 2013
Posts: 294
Likes: 10
From: Palmer Alaska
If you are using air for the test, that's a completely different 'animal'.
The conversion factor for leakage using compressed air, rather than oil, is approximately 7:1. Since you are using 40 psi, that would be the equivalent of applying 280psi of oil for that leak test. The volume of air escaping to atmosphere (assuming normal atmospheric pressure) is representative of that same volume of oil escaping.
I suggest that you lower the pressure to 20 psi. If the leakage is a gentle flow of air from the check valve, it's likely fine to reuse. If it has much force to the flow 3-4 inches away from the outlet, you may have a problem.
P.S. I do not have any specified value for leakage from that check valve. But it will leak some. You might back-flush that check valve to see if there is any debris retained in it.
The conversion factor for leakage using compressed air, rather than oil, is approximately 7:1. Since you are using 40 psi, that would be the equivalent of applying 280psi of oil for that leak test. The volume of air escaping to atmosphere (assuming normal atmospheric pressure) is representative of that same volume of oil escaping.
I suggest that you lower the pressure to 20 psi. If the leakage is a gentle flow of air from the check valve, it's likely fine to reuse. If it has much force to the flow 3-4 inches away from the outlet, you may have a problem.
P.S. I do not have any specified value for leakage from that check valve. But it will leak some. You might back-flush that check valve to see if there is any debris retained in it.
