Check valve question
 

I noticed that when i was replacing my vacuum chamber under the alternator that there was a metal check valve coming from the solenoid into the UIM its coming off the purge control....now my question is, is this supposed to be a one way check valve? because it is not doing much of anything...i dont have ne thing to compare it to so if ne one could enlighten me i would appreciate it

medal check valve?
they should all be plastic, their all 1-way also

alright thats what i thought...i dont know wtf its doing in there its not restricting flow at all its letting air back, think this would be my reason as to why im only getting 5 psi on the secondary?

yeah same thing is happening with me right now...look up "DaleClark" he sells Viton Check Valves here

i already know about them...i was just curious if ne one knows if that would effect a drop in 5 psi on the seconardy at all...with this check valve not operationg correctly....ahh fuck it ill just go replace and see.

It is perfectly normal to have one metal check valve coming off the front of the UIM i believe, that is a factory check valve.

alright...well is it a one way because this is not holding pressure going back to the solenoid...i can easily blow through both ends



<edit>Yeah i see on the diagram it is nevermind, this needs to be replaced...im guessing i can use a viton one or just another check off valve since i have extra other ones...(one way)...unless this has a different psi it is supposed to hold?</edit>

That ck valve has nothing to do with boost. It part of the fuel vapor recovery system, I dont think one of Dale's ck valves would be the best choice. But I've never seen the stock one go bad, you should be able to clean it with some carb cleaner

they arent all check valves, some of them are filters.

Doh!!!!!!! I meant one of Dale's ck valve's WOULD NOT be the best choice.

The metal check valve is part of the purge control system (fuel tank vent). It has fuel vapor running through it. A plastic check valve would not be a suitable substitute.

Pg F-129 in the FSM has a detailed description of it.

The direction of the arrow should point to the UIM (upper intake manifold)

It is a one way check valve. Test it, if it flows both ways you will need to replace it.

It's a dealer only item P/N is NF01-13-890 around $20 or so.

Call Ray Crowe @ Malloy Mazda the phone number is 1-888-533-3400. He will confirm if I posted the correct p/n.

If your curious if it is contributing to your boost problem you can plug the line & cap the check valve. Running it that way for a day wont hurt anything. The fuel vapor will vent through the charcoal canister near the rear diff (you wont smell anything).

The metal check valve has gone bad on both my FDs. Both were open in both directions. I doubt it would cause a boost problem. It is the cheapest check valve Mazda sales but I WOULD recommend one of Dale's check valves for this. Dales check valves are made out of Viton and PVDF (Kynar). Looking at the chemical compatibility...

http://www.coleparmer.co.uk/techinfo...e=&openlist=II

The Material Selected Viton®
Interacting with the Chemical Gasoline, unleaded
Has a Compatibility Level of A-Excellent

The Material Selected PVDF (Kynar®)
Interacting with the Chemical Gasoline, unleaded
Has a Compatibility Level of A-Excellent

Dale's check valves...

http://www.clubrx.org/default.asp?id...ntent=26&mnu=8

So I guess since Dale and I have been using these for a year or so means nothing ??? I would venture to guess you have some experience with them and this is where your knowledge comes from ? ? ? Please enlighten us as to where you obtained your facts for this recomendation.

Sorry dale, i bought those same check valves about a year ago on usplastics.com for like 2 bucks for 10

Dale's valves are too small for the purge line, the stock one is metal and can be cleaned and there can be liquid fuel in that line when the purge control valve opens, a failure of the valve (if he valve brakes open) would dump fuel and/or fuel vapor in to the eng. compartment, the metal stock one is less likely to fail. And just for clarifcation, I have replace all 4 of the stock ck valves for the vacuum lines with Dale's on my car they are a great replacment.

usplastics.com lists 1/4" check valves which are very close to the 6 mm I believe the purge lines are in size. The Viton and Kynar of these check valves is very resistant to gasoline. Plus they are about 1/10th the price of the failure prone Mazda valve.

I also wonder if the 3/16" check valves would fit better in the 3.5 mm or 4 mm silicone hose than the 1/8" Dale sells. The silicone should stretch that much.

The clarifacation makes things a bit more clear. I also retained the metal check valve and replaced all the others with Dales. By reading your post it would appear that they shouldn't be used at all, not just for the metal one.

Doh! Looks like Dale's source has been found. Oh well, I ordered mine from him and I don't mind paying extra because he makes some kickass writeups and is a helpful contributor to the FD community.

Heh Heh,
Got to make hay when the sun is shinning. He reaped a pretty decent harvest and probably helped a number of members with intermitten boost issues which in itself worth the price of admission. Most deffinately a contributor to the community. If he contributes half as much for the FD community as he did for the second gen group we will all benefit from it. Jack

The check valves I sell don't include one for the metal check valve, just for the 4 plastic check valves. I could probably spec a larger check valve to replace the metal one, but I was under the impression that the metal valve was more durable, and many times could just be cleaned with carb cleaner if it was stuck. I've torn a metal valve apart before, and it's a ball/spring check valve which is typically very durable.

I don't get my check valves from US Plastics, though :). The big thing with my valves is I'm buying them in bulk to pass the savings on, and I do take some exposure buying a bunch of check valves that will hopefully sell :). I do make some money on them of course, but it mainly compensates for my time, going to the post office, etc. etc. It's just a way to help make the hobby pay for itself a little. I'm definitely not getting rich off the sales!

On the size of the valves - the next size up is (I think) 3/16". I've got some samples, but the next size is just a little too big for me to be comfortable with. You really have to shove it into the hose, and I could see many people using too much pressure and breaking the nipple off the check valve. The 1/8" nipple check valves aren't as tight as I'd like on 3.5mm silicone, but with zipties they fit GREAT, I've yet to have one pop off or fail on my car, and have yet to hear of a fit problem from any that I've sold.

If anyone has any questions or anything about 'em, drop me a PM. I'm not on the forum as much as I'd like nowadays - my new job has me on the road all day instead of in front of a PC bored all day :).

Dale

Agreed, Dale. The cost of the check valves was more than reasonable when compared to the OE check valves.

awesome...ill try some carb cleaner on it and see if it holds...i still need to replace my other check valves anyway my CCA isnt holding so ill try the check valve first if not onto the solenoids fun fun fun :)