Headlamp washers: Deconstruction and possible fix

CatmanV2

Member
Messages
48,547
Hi all.

Finding myself with a 'spare' headlamp washer, I thought I'd have a look inside and see what repairs may be possible. The story so far:
My washer was wetting all the screenwash out in a steady drip. As far as I could tell it was coming out of the top of the collar through which the piston exits.

Here's a photo of the total assembly, you can just see the white seal

IMG_4741.jpeg

The nozzles are held on by one clip and friction of an o-ring on the inside of the piston:

IMG_4740.jpeg

In my case, I don't believe this o-ring was an issue. Worth noting that the washers appear to be identical on each side (although the caps are different). The nozzles appear also identical, but I didn't check the spray pattern.

Removal of the collar was a bit destructive. There are 4 clips moulded in which I had to shave down and then apply gentle persuasion on top of the piston while locking the collar against a solid opbject.. As expected, the unit came apart into a piston, a spring and an outer sleeve. Here we see everything lined up:
IMG_4742.jpeg

In operation screenwash is pumped into the bottom of the sleeve (cylinder) forcing the piston upwards agains the spring. When it hits the top, a small valve in the bottom of the piston opens, allowing the solution to flow up through the piston to the nozzles.

So at the base of the piston there is a blue seal the purpose of which is to seal the piston against the cylinder as it rises up. Although this looks in good condition, I suspect it was leaking, allowing fluid up the cylinder and then out through the collar. Not sure why this should have leaked all the time, though...

IMG_4743.jpeg

In any event, the seal and the o-ring on the nozzle can probably be replaced (although the seal is an odd shape, I suspect an o-ring would do just fine) Replacing the collar might require some remedial engineering depending on how bad the clips are mangled on disassembly.

If the valve at the bottom of the piston fails, I suspect it's game over. There's no way I can see to get to that, but also can't see any reason why that would leak *out*. If it failed open, I expect the washer to still work, although it'll probably be spraying as it rises.


Hope this is of help to some

C

I'll update as I find more.
 
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Oneball

Member
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11,075
You want some sort of sprung ring or two semi circles of brass with a chamfered end that you can use to open out the clips on the collar.
 

safrane

Member
Messages
16,748
I suspect that the only difference between makes is the top of the unit and where the spray patter comes out - the piston must be generic????

Maybe EBAY have some other cars items that could be compared.
 

CatmanV2

Member
Messages
48,547

That does look very similar, doesn't it? I can certainly imagine that the pistons are similar, but the overall rise is completely dependent on the length of the piston, so may not be a like for like.

My view ATM is that the piston is fine, just needs a new seal (unless the valve goes in which case, yes....

C
 

CatmanV2

Member
Messages
48,547
You want some sort of sprung ring or two semi circles of brass with a chamfered end that you can use to open out the clips on the collar.

I thing the challenge is you're having to stretch the complete circle. Some kind of tool might well be helpful. 4 small, curved wedges that can be tapped in might well do it. I don't think there will be too much trouble putting it back together. **** you could epoxy it as a one time repair and still be many many pounds up on the 'official' price. Self tappers might be a better bet as long as they are not too long

C
 

safrane

Member
Messages
16,748
That does look very similar, doesn't it? I can certainly imagine that the pistons are similar, but the overall rise is completely dependent on the length of the piston, so may not be a like for like.

My view ATM is that the piston is fine, just needs a new seal (unless the valve goes in which case, yes....

C
Not sure C; would the main water piston not dictate the amount of water that is sprayed whereas the riser would determine the height of the spray head from the bumper seating?
 

CatmanV2

Member
Messages
48,547
Not sure C; would the main water piston not dictate the amount of water that is sprayed whereas the riser would determine the height of the spray head from the bumper seating?

As far as I can tell, the 'cylinder' should be completely dry and sealed off by the blue seal. The piston is forced to the top of its travel by water pressure against the base. When it hits its maximum travel, the pressure builds enough to open the valve in the bottom of the piston, and fluid then travels up to the nozzle. So the rise is determined effectively by the length of the piston and its end stop. The amount sprayed (or at least the flow) will be determined by the flow of the valve at the bottom of the piston.

Does that makes sense, or am I missing something?

C
 

conaero

Forum Owner
Messages
34,593
A bit of a drift but also relevant, GT headlight washers, there was one at the factory and we bought it, they are sided. So they are currently NLA from the factory.
 

CatmanV2

Member
Messages
48,547
A bit of a drift but also relevant, GT headlight washers, there was one at the factory and we bought it, they are sided. So they are currently NLA from the factory.

The only 'siding' apparent on the Ghibli ones are a 90 deg rotation for the inlet pipe <shrug>

C