Plastic air tube connection

[Lin]

There is a small tee for the air going to my wipers (MC5a) mounted under the dash.  Two of the ports had a slow leak.  I removed the one connection I could get to with the intention of changing the ferril, but could not get the nut back on with a new ferril in it.  It appears to have the first trends are worn, so I could not get it to grab.  I am also using standard compression ferrils and have used them before with no problem.  Since it would not go back on the right way, I twisted Teflon tape into a string, wrapped it around the tube, and tightened the nut down.  It seated and is not leaking.  The question that concerns me is that, when using a ferril, it grips into the tube itself securing it in the nut.  I assume that my Teflon tape does not do much of that, so is this tube in danger of popping loose from the nut, or should the compression on it be enough to hold it in place?

[JackConrad]

Can the Tee fitting be replaced with one of the new "Push Lock" fittings?  Would require cutting about 1/2" off the end of each tube and simply pushing the tubes into the new fitting.  Jack

[Ncbob]

Lin, if you use the nut ferrule fittings you'll need to go to a supplier and get the sleeve to insert into the plastic which keeps it from collapsing under the tightening pressure of the nut. Or, as Jack says...use the push on type.  More expensive but effective.

Bob

[Sammy]

It's a safety item, so you can see properly in the rain - I recommend not make any temporary repair to it.
Fix it right, get a new fitting. Do not use teflon tape on nut for hose.
It requires a new fitting, new nut, new ferrule and new insert, or new "pushlock" style fitting which is DOT approved.

[Lin]

I do not know how the newer MCI's are, but these old fittings have the sleeve permanently attached to the male side of the fitting which has a 3/8" fine thread.  The stuff I find available is 1/2".  It would be easiest if I could find the right nut and ferrule.  Otherwise, I will have to open the access in the front and remove the wiper motor to get to it and, I guess, can replace it with anything.  Not that bad, but just another thing to do and I did I real good job of sealing it when I had the motor out to repair it.

[Dallas]

I do not know how the newer MCI's are, but these old fittings have the sleeve permanently attached to the male side of the fitting which has a 3/8" fine thread.  The stuff I find available is 1/2".  It would be easiest if I could find the right nut and ferrule.  Otherwise, I will have to open the access in the front and remove the wiper motor to get to it and, I guess, can replace it with anything.  Not that bad, but just another thing to do and I did I real good job of sealing it when I had the motor out to repair it.

Sounds like you are trying to save pennies... the fittings are made for everything from 1/16" all the way up to 2".. that I've used.

I've used the push on fittings, and they are nice, but at the cost I would only use them in places where I couldn't have easy access.
You say the the tube is permanently connected to the male side.. probably not, it was probably pushed in with the ferrule and nut and has deformed enough to be a PITA to remove.

In any case, I would remove the whole Tee and replace it. Most Likely about $5 at Napa or Fleet Pride or any Truck Parts Supplier.. like Pete, KW, Freightliner, Navistar, etc.


DF

[Lin]

Dallas,
     You are probably right in that if I can't get the right nut, I will have to go for the tee.  It is inaccessibly mounted behind that dash, but as I mentioned, I can get to it by opening the wiper motor access through the front.  I am not trying to save pennies as much as labor.  If my suspicion is correct though that this Teflon tape fix, although working for the moment, is unsafe, then I will have to do the labor of removing the front panels.  The added benefit to that is that I will be able to get to the other small leak that is not reachable from under the dash.  The male fittings on this, however, do have the sleeve as a permanent part.   Not only is it like that on this tee, but also on the connections to the wiper motors.  They work fine.  They all had some sort of plastic ferrule that were crushed and leaking when I got the bus.  I have, using the same male and female pieces, replaced those ferrules with brass ones from the hardware store which work fine.  This one, just would not grab though.   The other thing is that the closest Napa store is about 20 miles away in Twentynine Palms (home to the largest Marine base in the world at 3/4 the size of Rhode Island), and if they do not have what I need, I am looking at the 20 mile trip back and a 50 mile trip in the other direction.  All that is doable too, but I give first preference to managing with what is local or mailable.  I went to the areas only diesel shop yesterday, but he did not have the same stuff.  I bet that this is not the way people conceive of California.