Clearing a blocked car screen wash jet

[Jim K..]

+1 as you've removed the jet, can you check there's a good flow out the pipe? If not and the pumps working, there's a leak...

[Graeme]

Unbelievably, just discovered, four years after buying a car, that the rear screen has a washer as well as wiper :-)

Problem is, the jet, which angles the water 90 degrees, is blocked. Managed to clear a hole with a needle and very fine drill in pin vice, but not enough to allow a jet of water through. A small drop comes through, but nothing more. Unlikely to be scale as such, as this is a very soft water area. Any thoughts on what I could soak the jet in, to help? Put through the dishwasher last night, which softened the crud, and currently sitting in a cup of hot water with a dash of washing powder. Vinegar, perhaps?

[DerbyBorn]

of hot water with a dash of washing

Are you sure it is getting a flow through the pipe. It sounds like you have done what was needed. (Drill seems a bit over the top)

[jkn]

FWIW I have a small collection of 'wires' cut from old guitar strings when trying to clear blockages like this. You then have a variety of diameters, and the wound surface on the larger diameter strings is good to abrade the inside surface.

J^n

[newshound]

+1.

Often, the root cause is a gelatinous "blob" of fungus/algae/bacteria inside the body of the jet behind the actual pinhole. This is why clearing the jet with wire or a micro-drill doesn't always work.

Provided you can remove the jet to get at the backside you can often pull this gloop out from that side. Sometimes it can be pushed through with "guitar string" from the jet side but sometimes the geometry is unfavourable.

Obviously, check that you have a good flow through the disconnected pipe too.

[Brian Reay]

Good point. The pumps do jamb. You can sometimes get them apart and clean them. If not an it has jammed in the right position- so water can flow but not pump- you can fit a generic pump from Halfords in the pipe and connect the wires to it. I did the to my wife?s old Mk1 Panda when I couldn?t get a Fiat pump.

[Brian Reay]

Check the pipe isn?t ?nipped? somewhere. I had a CRV an one of the (front) jets was prone to not working- the only fault I recall having with the car. The pipe tended to move and wedge itself under the plastic trim bit, restricting the flow. Eventually I managed to secure it so it didn?t move.

Also, our Smart rear jet didn?t work. A joint in the pipe run had come adrift - fortunately it was accessible.

If you are sure it is the jet, replacements aren?t expensive- many are fairly generic. Try Halfords.

[Dave Plowman (News)]

Is the jet on the roof or tailgate? On my car it's in the tailgate. And the pipe to that via the hinges has a habit of flattening.

[Graeme]

In message [e-mail], jkn <jkn [e-mail]> writes

Brilliant. Thank you, I'll try that. Son is a guitar fanatic, so will doubtless have old strings lying around.

For the avoidance of doubt, yes, there is a good flow of water, just not through the final jet. The rear wiper had broken, so I removed and repaired, and tested without replacing the cap over the spindle. Flicked the switch and was amazed to see a jet of water shoot out. Not being a top of the range model, I had always assumed a washer was not fitted at the rear. Now I know it is there, I'll try the guitar spring trick.

The drill I tried was very tiny - probably less diameter than the average sewing needle.

[Jethro_uk]

Blocked non-return valve ?

[Dave W]

Now you've softened it, perhaps a bit of added pressure or suction might help, e.g. hypodermic needle?

[Graeme]

In message [e-mail], Dave W [e-mail]> writes

Job done! I think sitting in hot soapy water softened it, and a combination of guitar string, contact cleaner and a can of compressed air finished the job. Delighted :-)

[Mr Pounder Esquire]

Had a similar problem many years ago. I used to top up the washer bottle from a kettle. The kettle needed descaling and bits of sediments were being introduced into the washer bottle. Lesson learnt.

[Andrew]

If you have a syringe, attach a short section of flexible tubing to the syringe nozzle and try and back flush the car jet.

If you can get at the rear of the car jet and remove the tubing, even better because you can isolate the blockage to be car jet or tubing.

[Harry Bloomfield]

Graeme explained on 11/06/2019 :

Remove the pipe from the jet and make sure there is good flow out of the pipe. Sometimes there is a sort of jelly like substance which grows in pipes, blocking jets. Easy way to clear them is with compressed are, blown in from jet end of pipe, towards the bottle, making sure there isn't a one way valve in the system.

[Graeme]

In message <qdqbfl$9av$ [e-mail], Harry Bloomfield [e-mail]> writes

The problem, now cleared, was not the jets. No idea whether they're all the same, but on this car, the water comes through a hole in the wiper spindle, to be met with a cap which turns the water through 90 degrees, and directs it through two jets. The blockage was within the cap, before the jets, and whatever it was, was solid. Softened by running through the dishwasher, then soaking for hours in a cup of hot water with washing powder. Much squirting of contact cleaner (which may or may not have helped), poking with a tiny screwdriver and old guitar strings and blasts from a compressed air aerosol. Now working perfectly.

[Harry Bloomfield]

Graeme used his keyboard to write :

Thanks, yes probably the jelly like substance. It can be quite difficult to clear out.