kc559moho Report post Posted September 29, 2020 1/8" tubing on mech oil press. gauge very slow for diesel pusher.should 1/4" be used? Share this post Link to post Share on other sites
wildebill308 Report post Posted September 29, 2020 What make and model has a that? What year, what engine? Bill Share this post Link to post Share on other sites
hermanmullins Report post Posted September 30, 2020 KC what size is the fitting on the back of the gauge? I think the gauge operate on pressure not volume. I think you are OK with what came on the gauge.(1/8") IMHO Herman Share this post Link to post Share on other sites
kc559moho Report post Posted September 30, 2020 Thanks for the input Herman and wildbill , sorry I didnt leave more info . 99 National Tradewinds 36'6".Autometer gauge has 1/8" fitting on back. Iran at 1100 PM for about 5 minutes before it started dripping . put it back together and gradually got to 50 psi but that seems too slow. cat 3126 ,fresh oil ,no leaks. could manifold be plugged on the outlet I used. Dash gauge responds fairly quick but it's just a low or high gauge . ( reason I went with a mech.gauge. Share this post Link to post Share on other sites
richard5933 Report post Posted September 30, 2020 Are you talking about a mechanical gauge in the engine bay or up front in the dash? If it's in the engine bay, I'd check for something in the manifold blocking the works. My engine bay gauge mounts directly to a small oil pressure manifold block on the bulkhead. The 1/8" line should be adequate, if the path is clear. If you're talking about having a mechanical gauge on the dash with tubing running all the way back to front, then I would expect there to be quite a delay in the reaction time. Probably why electric gauges are usually installed. Share this post Link to post Share on other sites
wtbuck12 Report post Posted September 30, 2020 Unless there is air trapped in the pressure line, the response time should be minimal. Oil does not compress significantly and 50 psi on one end of the tube should transmit to the other end quickly. Just my opinion Ronnie Share this post Link to post Share on other sites
kc559moho Report post Posted October 2, 2020 thanks for the input . I took both ends loose and put air to it and still just drips . checked oil manifold and all is clear. so I tore 1/8 " copper tubing out and increased tube, block fittings and final conn. at gauge all to 1/4 " and works great. after further inspection of 1/8 " that I removed I found 1 spot where it was oval instead of round , definitely not kinked but it was enough. I would strongly recommend 1/4" tubing for anyone who wants a mech. gauge on their dash when it's a 40 ' away from there motor. Share this post Link to post Share on other sites
wildebill308 Report post Posted October 3, 2020 I would rather have a quality electric gage because it is faster and probably more accurate. Bill Share this post Link to post Share on other sites
richard5933 Report post Posted October 3, 2020 They used to put both - I've got an electric on the dash for regular use, and a mechanical wet gauge in the engine bay. The mechanical one is more reliable and helps when there is any reason to question the electric. Share this post Link to post Share on other sites
jleamont Report post Posted October 5, 2020 On 10/2/2020 at 8:31 PM, richard5933 said: They used to put both - I've got an electric on the dash for regular use, and a mechanical wet gauge in the engine bay. The mechanical one is more reliable and helps when there is any reason to question the electric. Good idea! Given the distance from the dash to the engine I would be concerned of that capillary tube failing over a basement or at some point between the engine and dash, not knowing about it until you see oil running out of the basement or worse, when the engine runs dry and locks up. Share this post Link to post Share on other sites
