Truck has 71000 miles. The washer pump was replaced under warranty several years ago. Last year, I took it in because the washer nozzles were not spraying above the wipers at highway speed. The service department stated that there was debris in the tank, drained, blew out the lines with air, and stated it was fixed. Driving home it was better, but definitely not working properly. A year later and the same symptoms have returned. I initially accepted the debris in tank, but highly doubt that is the problem. The nozzles spray equally, but at a reduced volume. I run quality cleaner in the tank, keep it full, and never experienced an issue in my other vehicles over the past 40 years. Any ideas?

 

I would check for a kink in the hose somewhere or possibly a small pin hole in it.

 

I agree to check that first. Let's rule out the simple stuff first. Also, if there was debris, the check valves or nozzles could be plugged up. The check valves are under the cowl panel and are easy enough to service.

If that does not fix the issue, you may need to look at the pump or the wiring to the pump. Test for voltage using the power and ground at the connector to see if there is a low voltage condition.

 

Rain-X Fluid or similar will leave debris and plug pumps and lines.

 

I have not used RainX or any other silicone based coatings for many years. The residue that is leaves behind when its effectiveness breaks down creates wiper issues. Safelite told me to avoid RainX because it interferes with the repair process for rock chips, too.

The dealer checked the wiper motor last year when the problem first developed and stated it was fine. I may replace the check valve assembly that is covered by a TSB.

 

Checked on here to look for suggestions. Usually get a windshield washer topping at the dealer when servicing but thought I would add some myself. BMW Forum recommended BMW wash due to clogging with other brands. Could be a myth. I dunno?
The RainX sounded good but think I'll just go with Peak or SuperTech, keep the colors the same and stick with a non-silicone based product for my 2014 F150.

 

The tank cap does not provide a seal for the tank. If you drive in a dusty environment, you can get enough gunk buildup to clog the pump intake. I'd pop the pump out to see what it looks like.

 

False. MIXING Rain-X with other windshield washer fluids, such as the regular old, "Blue stuff", will cause problems. Ask me how I know... At any rate, I've been using exclusively Rain-X washer fluid (except that one time...) for almost 20 years and have never had any issues at all with any of my nozzles, reservoirs or pumps. Also, don't believe anyone that says it will ruin your paint. Again, never had that experience with either the green or orange stuff.

 

I'd love to know where these people get their info. I recently repaired a rather significant rock chip in my windshield, myself. If you take the time to CLEAN the repair area and do the repair properly, then the Rain-X is a non-factor. Does this guy think that Rain-X is some magical potion that seeps into the glass, or something?

 

Rain-X does not affect chips, but it will prevent epoxy from filling spider webs, which I'd never accept as a repair, because the cracks do not become completely invisible, some epoxy is inevitably left on the surface creating a lens, and the cracks can continue to propagate.

I've also Rain-X fluid without issue for decades, almost four of them. I always run out whatever was previously in the tank before switching to Rain-X so it isn't diluted. I can totally believe that mixing it with other fluids may cause issues as we've got that exact problem with our coolant.

The only vehicles I've ever dealt with washer pumps clogging up were those whose owners put in whatever fluid was cheapest when they ran low, or had the nearest a garage fill them up when they ran out. There are thousands of chemicals that have the properties that are needed for washer fluid, and undoubtedly some of them won't play together well and will generate precipitate when mixed. As long as you don't mix fluids, and don't let your tank run too dry (evaporation deposits), you'll probably never experience any issues.