pressure & vacume test ?

[ziggy]

i'm a bit confused about this. (regaurding my trisonic listed below)<br />1st off i guess is where can i get a hip gage that will read up to 15 psi. i used one of those combo fuel pressure vac. gages. but the psi side only goes up to 10 psi. tried multiple places w/o success finding one to go to 15. so anyways, i tested my drive at 10. hope that was enough(not the way i get it though from readin here on iboats). no leakdown. left it on 15 min. or so. <br />then did the vac test. that one disappointd me a little. did 7hg of vac. it leaked down to 5 easy within a couple of min. so what is this telling me? seems like i'm treadin on thin ice perhaps. i also just speedi sleeved the drive shaft for the very bottom seal in the upper. should that be my first suspect?

 

[Don S]

Re: pressure & vacume test ?

My first thought would be the vacuum leak is probably from the input shaft seal (Ujoint shaft)<br />That seal is not designed to keep water out, the bellows is supposed to do that, so they usually will only hold between 5 and 10 in. of vacuum.<br />To make sure, just point the ujoint straight in the air and fill the cavity with thick oil (90W is great) and try your vacuum test. If it holds then you know the parts under water are ok.<br />The pressure gauges don't have to be fancy, any small gauge that will read 15 psi will work. If you have 10 psi and don't have a leak, they it probably won't leak at 15 either.<br />Are you getting water in the drive or what? Must be some reason you are trying the P&V tests.

 

[ziggy]

Re: pressure & vacume test ?

DonS, thanks for the input, i feel a little better now with yer statement. yep. there's a reason. at first startup for the year i over heated. bad impeller. so did me a impeller, waterpump upper and lower houseing, lower seal on the upper drive shaft houseing, water pocket cover on the upper drive shaft houseing along with 3 helicoils in the upper drive shaft houseing (broke off the SS bolts to the water pocket cover)had a groove in my drive shaft from the lower seal from the upper drive shaft houseing and speedi-sleeved that. also a t-stat. i did the P&V test on the boat as i only had the lower off for the repairs i did. <br />also i did have one thought, the drive had been seperated for a month or so. so was thinking that there wasn't any gear lub left in the drive at all. bone dry i'd think. don't know if that will have an effect on the P&V test. <br />just trying to make sure i'm hip before i have a problem (hence trying to understand the P&S readings). i figure i'm on thin ice with my speedi-sleeve. which i know is not the proper repair. but i'm a poor boater so am trying to get away with it. if i don't, well, i tried and will then move on to a more proper & expensive repair. but for now i'm just trying to make sure that i at least feel like i was successfull with my engineering before i throw it in the lake. <br />one last note. i did fill'er up with gear lub and fired it up on the hose. stayed cool just fine, yeh, aslo took the lower drain screw loose and found clean gear lub afterwards. so far so good. but the hose ain't the lake at WOT i don't reckon......

 

[achris]

Re: pressure & vacume test ?

Ziggy,<br /><br />Sounds like you have a good grasp of what's what.I like people who can make staements like

but the hose ain't the lake at WOT i don't reckon....

Don's pretty right about the vac leak. Unless that seal is brand new out of the box, it will leak a bit. I also wouldn't worry too much about being dry for a month, a year, yes, but not a month.<br /><br />Good luck,<br /><br />Chris..............

 

[KaGee]

Re: pressure & vacume test ?

Ziggy,<br /><br />You can make up a rig like this very reasonably.<br />You'll need a combo pressure/vacuum gauge, pump, T-hose fitting, hose and the metal fitting robbed off of a lower unit oil pump kit.<br /><br />

<br /><br /><br />Substitute a vacuum pump for the air pump.

 

[ziggy]

Re: pressure & vacume test ?

thanks for the comments peoples. you have all been very helpful and had very good suggestions. from the comments i guess i have done the best i can. i was just concered about the low pressure (10 psi)test and the vac test that leaked down. kagee. thanks for the above pic. i have seen it posted before, and yep. thats the set up i went with and it worked well. i just didn't have a gage to read 15psi. only 10. used that mity vac pump for $38 from the auto parts store. it worked very well too. sounds like a lake test is next in order to see if i was successful with this...... ziggy