Plumbing mystery--faucet leak - PeachParts Mercedes-Benz Forum

kerry · #1 08-02-2008, 06:26 PM

I've got an apt with an old cast iron sink and the classic kitchen faucet coming out of the wall above it. Chrome fixture, hot and cold joining together in a spout that spins side to side. Had a serious continuous drip. Figured it was washers and seats. Took it apart. Sure enough, washers were shot and seats were worn out. Replaced seats and washers. Put it back together and turned on water. Still had a steady continuous stream with the faucets off. I've taken it apart about 5 times, checking that seats are tight and washers are correct and in position. No difference. I still have a continuous steady stream of water about an eighth or a sixteenth of an inch wide. Anybody have any idea what is going on? Could that much water be getting by the seats? Seats looked to be identical replacements although on old faucets it is hard to tell. The were 9/16 but threaded into the 18,20,22,and 24 threads per inch holes in the test board. I think the replacements were the 18 threads per inch. Could the water be getting by the threads?
Washers seem to be working. Open the taps and water flows. Close the taps and water shuts off promptly except for this continuous flow which seems totally unaffected by how much torque I put on the taps. It's almost as if there is a separate supply of water causing the stream, independent of what is going thru the seats and by the washers.

cmac2012 · #2 08-02-2008, 06:40 PM

Could be some unrepairable corrosion around the seat.

Probably not the answer you wanted, but I had the same thing in one of the units of one of my clients, and I bought a whole new fixture -- about $50, has the quarter turn ceramic valves. It's like Lexus compared to a beat up 30 year old Toyota.

The down side was getting one of the nipples out, needed to do that because one of them was corroded enough so that it wouldn't hold water once I put it all back together.

Brian Carlton · #3 08-02-2008, 06:45 PM

I'll take a guess at this mystery.

If the new seats are slightly shorter than the original seats, the distance that the stem needs to travel is increased. This would normally work fine............if the stem has that travel available. If the stem is limited on travel, it runs out of threads just before the washer contacts the face of the seat (maybe .020" short) and it allows the flow that you describe.

Put some bluing on the face of the seat and close the stem. See if the bluing transfers to the entire washer face. Then you'll know.

The only other possibility is the face where the seat contacts is totally corroded and the threads are also shot. This should allow a drip............I cannot imagine that it would allow a stream.

kerry · #4 08-02-2008, 06:46 PM

I need a better answer than that.

I considered replacing the whole faucet but those nipple coming out of the wall are probably 100 years old so the odds of replacing them without extensive plumbing work seem pretty slim. The sink is a cast iron original, the kind where the back of the sink runs up the wall about a foot or so and the faucet holes are in this cast iron piece so the nipples are going to be a bear to access.

Larry Delor · #5 08-02-2008, 06:49 PM

Are new washers Flat? If they are, might it be that they are supposed to be the trapazoid looking ones? There isn't any extra packing at the top of the stem, is there?

kerry · #6 08-02-2008, 06:51 PM

Quote:

Originally Posted by Brian Carlton

I'll take a guess at this mystery.

If the new seats are slightly shorter than the original seats, the distance that the stem needs to travel is increased. This would normally work fine............if the stem has that travel available. If the stem is limited on travel, it runs out of threads just before the washer contacts the face of the seat (maybe .020" short) and it allows the flow that you describe.

Put some bluing on the face of the seat and close the stem. See if the bluing transfers to the entire washer face. Then you'll know.

I don't see any other possibility.

I considered that. I have coned washers on there and the washers are pushed down hard uniformly when I look at them upon disassembly and I can feel the washers compressing as I torque down the taps. The main flow is stopped with very little effort on the taps. I can torque them down further once the main flow stops but it has no effect on the small stream of water.

Larry Delor · #7 08-02-2008, 06:54 PM

After reading that, I'm all tapped out of ideas.

kerry · #8 08-02-2008, 07:37 PM

Quote:

Originally Posted by cmac2012

Could be some unrepairable corrosion around the seat.

I'm leaning towards this answer. I may pull the seats again and inspect it closely before condemning the fixture.
I have a similar fixture sitting around. They are attached to the pipes with a union but I don't know if the threads on those unions are standard so I could just unscrew the union and install the other fixture without having to mess with the nipples.

Larry Delor · #9 08-02-2008, 07:54 PM

Undoing a union can be a can of worms too - be careful.

KarTek · #10 08-02-2008, 09:31 PM

They (somebody) make(s) seat re-conditioning tools. It consists of a handle that threads into the valve body and has a reamer on the end for re-shaping the seat. I have one at home but I'll be danged if I know where it came from...

Brian Carlton · #11 08-02-2008, 10:17 PM

Quote:

Originally Posted by kerry

I considered that. I have coned washers on there and the washers are pushed down hard uniformly when I look at them upon disassembly and I can feel the washers compressing as I torque down the taps. The main flow is stopped with very little effort on the taps. I can torque them down further once the main flow stops but it has no effect on the small stream of water.

I've never been successful with the coned washers. Does this assembly require them or can you use flat washers?

KarTek · #12 08-02-2008, 10:18 PM

This is what I'm talking about:

http://cgi.ebay.com/Sexauer-Tight-Line-Bibb-Faucet-Valve-Seat-Forming-Tool_W0QQitemZ350061142998

Rob Pruijt · #13 08-03-2008, 05:53 AM

Once a old faucet leaks the seat wears out and have to be reamed. Universal tools are cheap, I bought a complete set for $5,- . Also disassemble, clean and lubricate (faucet grease) al moving/turning parts. A 10 minute job and the faucet works like new!

Rob

kerry · #14 08-03-2008, 10:01 AM

I put brand new seats in the faucet so they shouldn't need any work. I did not try flat washers and I'm not sure what was OE. I think the next step will be to disassemble, take a close look for corrosion, reassemble with teflon tape on the seat threads, install flat washers and see what happens.

kerry · #15 08-04-2008, 02:14 PM

Problem solved. Took it apart and put 8 or 10 turns of teflon tape on the threads of the new seats. Leak stopped. I suspect that the threads on the new seats were too coarse. They threaded into the faucet but weren't sealing adequately allowing a small amount of water to seap around the seat. I looked closely inside the faucet and saw no corrosion.