News:

The ORG - No shonky business!

Main Menu

Headlight washer hose diagram

Started by raueda1, 08 June 2018, 11:30 AM

raueda1

Another day, another project.  Today's is replacing old, discolored and gross looking windshield and headlight washer hoses. 

The windshield washer circuit is straightforward and works fine.  The headlight washer circuit is weird however and I don't quite understand it.  I've been unable to find a diagram for it, but there is this thread on the topic:  https://forum.w116.org/interiors-and-exteriors/is-there-2-washer-motors/msg69536/#msg69536

To quote from that thread:  > the headlight washers are a bit different, a hose from reservoir to pump, a hose from pump back to tee-piece on top of reservoir filler cap, a third hose from tee-piece then runs down to headlight nozzles via an inline valve of some sort.<

I don't understand the return from the pump to the T on the filler cap.  It seems like the T would simultaneously send fluid to the nozzles AND back into the tank.  Seems like a strange design.  To make matters worse I don't have the original T.  if there's anything special about it I'm out of luck.  I do have the anti-siphon check valve in place as described. 

If anybody can explain or provide a diagram I'd be very grateful.  Thanks in advance and cheers,

-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

tcj

Hi rueda,

the description is correct. The T is the problem. Often broken and NLA for years. I don't know a replacement.
I do have a spare, but don't want to sell it as it should remain for the years of my 6.9 that are coming.
If you look at pictures of the engine bay of 6.9s you will find that >80% have no T anymore.
4 washer hoses should end on top of the washer reservoir (6.9)!

There is a tiny hole at the bottom of the T so I think it works as a bypass to prevent too high pressure in the line.

I think I have a NOS check valve for sale. If interested please send me a PM.

Thomas
112.021
113.042
116.028
116.036

raueda1

Quote from: tcj on 08 June 2018, 01:28 PM
Hi rueda,

the description is correct. The T is the problem. Often broken and NLA for years. I don't know a replacement.
I do have a spare, but don't want to sell it as it should remain for the years of my 6.9 that are coming.
If you look at pictures of the engine bay of 6.9s you will find that >80% have no T anymore.
4 washer hoses should end on top of the washer reservoir (6.9)!

There is a tiny hole at the bottom of the T so I think it works as a bypass to prevent too high pressure in the line.

I think I have a NOS check valve for sale. If interested please send me a PM.

Thomas
Ah ha!  The T actually IS a bit special.  Thanks Thomas! 

My car actually had the T when I got it, but it broke when I was cleaning things up.  Very old, very brittle.   I just substituted a generic car parts store T but couldn't figure out why it was hooked up as it was.  Anyone would have to look very closely to spot that it wasn't the OE part.   So, maybe the thing to do is just use what I got and play with the size of the hole in the bottom.  Do you know about how big the hole in the bottom is? 
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

tcj

Hi raueda,

the hole is 0.55mm

Thomas
112.021
113.042
116.028
116.036

raueda1

Quote from: tcj on 09 June 2018, 03:01 PM
Hi raueda,

the hole is 0.55mm

Thomas
Wow!  That IS small.  Thanks for that.

In the meantime I found the remains of my broken T and the bottom hole sticking through the round lid is the same as the others, roughly 2mm I guess.  Maybe my T is the wrong one.  Unfortunately it's academic for me at this point since my pump isn't pumping.  Wipers are working fine.  Gotta trouble shoot that now. . . . .
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

tcj

Hi raueda,

take a closer look: the bottom end of the T is 3.3mm (like the others). But if you make a deep look into this 3.3mm-hole you can see
that there is a smaller hole (0.55mm).
112.021
113.042
116.028
116.036

raueda1

Quote from: tcj on 09 June 2018, 04:52 PM
Hi raueda,

take a closer look: the bottom end of the T is 3.3mm (like the others). But if you make a deep look into this 3.3mm-hole you can see
that there is a smaller hole (0.55mm).
Amazing!  It's there!  It's just a pinhoie.   If you didn't know it was there you'd never see it in a 1000000 years.  I can duplicate that on my replacement T easily enough.  Now just to get the pump going . . .    Thanks much!!
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

tcj

Hi raueda,

im am Interested: How is your replacement T looking like? Do you have a photo?
112.021
113.042
116.028
116.036

raueda1

Quote from: tcj on 10 June 2018, 01:28 AM
Hi raueda,

im am Interested: How is your replacement T looking like? Do you have a photo?
It's just a generic T for vacuum or washer applications from a car parts store.  It's roughly the same size as the original except, of course, the fit through the cap on the tank opening isn't perfect.  But it's pretty close.  A pinhole orifice shouldn't be hard to figure out.  But I can't confirm until I get the pump working again.  I suspect that it isn't getting power from the whole relay interconnection with the wiper so it may not be easy.  Stay tuned.  I wish to join the exclusive club of W116 owners with 100% working headlight washers.  ;)  Cheers,
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

raueda1

Look what I found.  Hopefully of use to somebody, sometime.
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0

tcj

Yes, but the first diagram is only for the non-6.9-cars. These cars have the "T" (#14) at another location.
The 6.9 does have that T at the cap of the washer bottle.
112.021
113.042
116.028
116.036

raueda1

Quote from: tcj on 10 June 2018, 02:45 PM
Yes, but the first diagram is only for the non-6.9-cars. These cars have the "T" (#14) at another location.
The 6.9 does have that T at the cap of the washer bottle.
True, but still useful, especially the wiring.  Anyway, I did get the system working right, which is very exciting.  I'll need to mess around a bit to get the T hole right.  For sure, it does NOT work properly without the tiny hole.
-Dave
Now:  1976 6.9 Euro, 2015 GL550
Before that:  1966 230S, 1964 220SE coupe, 1977 Carrera 3.0