2010 Silverado 1500; 4.8L
My truck has a slow power steering leak. I top it up with 100 ml of power steering fluid every 500 km. I had a shop replace one of the power steering lines, thinking there was a leak in the line, but the leak persists.
I'm not able to get a mechanic to investigate the issue in the near term. So I'm considering trying a stop leak product like Lucas Oil Power Steering Stop Leak, 355-mL.
Are there any known risks with using power steering stop leak products?
Stop-leak products work by a number of different mechanisms.
Some of them contain a chemical that tries to make the rubber seals in the system soften, swell up and seal joints more tightly. This sometimes (not always) stops the leak, but can break down the seal over the longer term and cause the leak to get worse later, or cause seals in other parts of the system to start leaking as well.
Others contain particles, chemicals, etc which are supposed to "clot up" and form a plug in the leak. Again, this doesn't always work - and sometimes this style of stop-leak can form clogs elsewhere in the system (like in small valves or precisely drilled holes) which may cause more serious issues with system function.
If you are planning to replace the car soon and just need to get a few more hundred km out of it, trying a stop-leak product might work in the short term - but in that case, it's about the same price to just buy another liter of power steering fluid and top it up.
On the other hand, if you're looking to keep the car for a long time, I'd prefer to just keep topping up the fluid until I could afford a proper fix, rather than risking a stop-leak product which has a chance to damage the system and make the fix much more expensive.
To help identify the problem for when you can afford another trip to the mechanic, I'd also get a UV leak detection kit. More detailed instructions are available online, but basically - you clean the leaking fluid off of the area, then add a little bit of UV sensitive dye to the steering fluid reservoir. After a short drive, you inspect the suspected leak area with the UV light from the kit and you should see glowing dye around the source of the leak. Then you know exactly where the long-term fix is needed, and can take photos to show your mechanic.
