I have a 2006 Toyota Highlander (V6 Limited) and I am going to be replacing my rotors and pads and doing a brake fluid flush soon. My question is can I use DOT 4 to replace the DOT 3 in the system? I know the manual calls for DOT 3 but I am considering using DOT 4. I know they are compatible with each other but are there any cons to using DOT 4 in a DOT 3 system?
DOT 4 is the latest and greatest.
So that’s what you use.
I’ve had quite a bit of maintenance items related to the brakes in my '07 V6 Sport. I can’t speak to your specific issue. I’d stick to the script. I’d check each caliper to ensure it’s not frozen (look for uneven wear on one side/corner of the vehicle and excess brake dust). I’d also give the parking brake a full service as well. Good luck! Here is a story about my Highlander you may find of interest. https://www.torquenews.com/1083/real-world-costs-maintain-toyota-highlander-100k-miles-will-shock-you
We love our Highlander and I hope that when my last son goes off on his own to take it back and do a full overhaul on it and make it our utility vehicle.
Dot 3 and 4 mix just fine. Dot 4 has a higher wet and dry boiling point. There is no downside to using Dot 4. Just change whatever you choose every 3 years to keep it fresh and dry and help prevent internal corrosion of your brake system.
If you haven’t changed the fluid before, buy enough to do a full brake fluid change. The first change in my last car, I bought the DOT4 fluid with the highest boiling point I could find. It worked very well.
My mother has 228k on her 2007 Highlander. Recently discovered a frozen rear caliper. Front one blew up a while back.
The 3.3 V6 is awesome. I’ve had to do valve cover gasket, a couple of coil packs (the rear ones are a real treat). I put all new hoses in at 200k as preventative maintenance. There is a rubber coolant hose mounted UNDERNEATH the intake manifold. That was kind of a disappointing design decision. However, to their credit, Toyota put protective sleeves on all of the hoses that are in areas of excessive heat or friction. Had to have a new A/C condenser in also. Overall I think Toyota was really on their game with this vehicle. Hers just happened to come with the towing package which included an auxiliary trans oil cooler. I really believe that those can be the difference makers in trans longevity, regardless of towing or not.