P80 Windshield and Headlight washer pipework

[scot850]

This may not be a totally correct guide to these system as I am finding difficulty finding information on 850 models and it has been a long time since I worked on these systems on those. It will be close but feel free to correct if you have an 850 or even a V/C/S 70 P80 and correct.

This was prompted by a question from a member a few weeks ago who was finding it took a long time for the water to come out of the jets on his 850.

There are 3 possible set ups on P80's and there are some differences and I will try to cover those, hopefully correctly!

Sedans without headlight washers

These are the simplest systems. The P80's have a pump built into the washer bottle. With lack of use and using hard water these can seize up. If you are careful they can be removed, cover removed, cleaned, lubed and re-installed. I have used Pro-Parts pimps and Volvo and neither seems better than the other.

The pipe runs from the bottom of the tank up the RH inner fender and then held by clips up the RH hood hinge before disappearing under the sound deadening material.

I may be incorrect on 850's but I believe they have a valve prior to the RH washer jet. There is a one way valve built into a offset 'T' connector which then feeds water to both the jets. The valve is there to keep water in the pipework up to the jets for quicker operation when the washer lever is operated.

The valve is a simple diaphragm made of rubber and over the years this can fail allowing water to run back to the washer bottle which makes it take a lot longer for water to reach the jets.

The second issue is they have small nozzles internally that can block. Owners then remove these and find the jets work and throw it away giving the same issue of slow water response.

The valve can be carefully opened and cleaned and I will detail that later. If the diaphragm fails then replacement is the only option.

V/S/C 70 windshield washers operate in a similar fashion. The only difference is there are 2 valves, positioned just below each of the jets. This gives faster water response when the washers are activated.

Pictures below:

RH washer jet in hood

PXL_20220219_214805567.jpg (3.26 MiB) Viewed 1492 times

The RH jet is a 'T' unit with a flow through connection to the LH jet. The valve cover is the round cap below the 'T'

LH washer jet.

PXL_20220219_214812602.jpg (2.83 MiB) Viewed 1492 times

The LH valve is a simple 'L' shape again with the Valve below it.

The valve can be opened using a small sharp blade like a watch maker screwdriver but be careful not to damage the cover.

Valve components

PXL_20220219_234230874.jpg (3.76 MiB) Viewed 1492 times

Inside the unit is made up of a simple piston valve cap with a spring under it.

Piston cap hole

PXL_20220219_234338260.jpg (2.15 MiB) Viewed 1492 times

In the valve top there is a very small hole for water to come through and is one area that it can block.

Valve cover hole

PXL_20220219_234420157.jpg (1.81 MiB) Viewed 1492 times

In the side of the valve cover there is a second small hole so again make sure it is clear.

Finally there is the rubber diaphragm. As you can see in the sample below it is quite worn and has a build up of dirt on it. This can prevent the diaphragm sealing correctly allowing the water to run back to the water bottle. Cleaning the diaphragm may fix this, but you can also reverse the rubber and it will then seal better against the plastic cover.

Rubber diaphragm

PXL_20220219_235311112.MP.jpg (5.8 MiB) Viewed 1492 times

Once clean reassemble and the cap clips back into the valve body.

I see no reason the same later system could not be added to the 850 system if you want to.

Wagons:

Wagons have a 2nd pump in the top front of the water bottle. It sits higher than the front windshield pump to ensure if the level gets low, the front windshield get water for longer while the rear will not get water.

The pipework to the rear is separate to the front windshield. I have herd different opinions but I recall there is a valve on the front RH inner fender leading to the rear washer. Again lack of use will cause the pump to seize more quickly than the fronts.

Headlight washers.

These are fed by the from front windshield washer pump. Again there is a one way valve in the system. Again a simple T shaped unit but with only one valve working for both wipers. This valve is hard to access but can be found under the RH headlight. Removing the headlight gets better access to being able to fish it out to replace or clean.

If you decide to do a headlight washer delete, what I see is people removing the valve and tying a tight not in the pipe to prevent water flowing out.

If you find your washer fluid is disappearing quickly, it is possible the pipes to the headlight washers has split.

Windshield washer jets.

I have heard of complaints of the quality and direction-ability of pointing the jets. I have upgraded my 2000 Volvo V70 jets to P2 jets following a conversation with a Volvo mechanic. They do work a lot better!

Hope this is of some help and feel free to criticize and correct!

Neil.