I have a random pulsating problem while braking (hard or soft). This is a 1999 F350 DRW 6SPD with an all manual drive train. I pulled the front rotors, had them inspected and they are in great shape. During the process of removing the rotors I found my passenger side ball joint (lower joint ) was in bad shape. I replaced upper & lower joints thinking maybe the braking issue could be related to the bad lower ball joint. After test driving, the braking seems to be less intense, however it is still there. My question is; can the ABS sensors control braking to a point that if a sensor is not working properly it could cause what feels like pulsating brakes? Again, this is a random braking problem. Sometimes the brakes work perfect (hard or soft ) with no pulsation and maybe three or four applications later light pulsation happens.

 

How old is your brake fluid and your ps fliud?

 

I have aprx 150000 miles and 10 years on them. I did do a brake bleed to see if that might help and did notice the bake brake bleed resulted in a little darker fluid than the front.

 

You should flush out the old fluid and add new in both the brake system and the ps system. The ps pump is part of the braking system, make sure that you use synthetic ATF in the ps pump.

 

Did you just bleed the lines, or flush all the fluid? You need to do a complete flush on the brake fluid, and also flush the ATF in the power steering/hydroboost system.

 

(Thank you) I will make that my next on the to do list. I did question the brake fluid but not the power steering. I think your steering me in the right direction.

 

You might also want to check your brake caliper pins. I was getting a pulsating in the brake when my pins started to seize.
JEV

 

Well today I flushed out the P/S fluid. I used 3.5 Qts during the flushing process and then used part of the 4th quart to top of the reservoir. While I was in the flushing mode it seemed to be a good time to flush the brake system as well. With both those jobs out of the way it was time for the road test. I drove approximately 4mi R/T and included some fairly step down hill grades. As of now all the pulsation is gone but the best part is WOW my brakes feel like BRAND NEW. The advice I received from FTE was right on. I used the #2 method for the P/S system and followed the procedure F350-6 suggested and it worked out to be easier than I thought. The only change I made was were I put the drain hose. I used 3 ft of 3/8 clear hose over the fender onto a step stool and in to 1 gal old antifreeze container. I simply drilled a 3/8 hole into the lid of the container and pushed 2 inches of the clear hose inside the lid, then fasten the other end of the hose to the return line and then I started up the truck. I checked to make sure the reservoir was full and because I did this procedure alone I found was able to pump the brakes 12 (easy and steady) times then refill the reservoir until the the fluid running through the clear hose looked the same color as the new fluid. Using this link Power Steering Fluid Flushing Procedure For F250 Superduty Truck was a perfect example on how to do a P/S flush that I have seen. Thanks Again F350-6 your info kept me from wondering if I could do it, to doing it.

 

Yeah, Chris knows a lot about these trucks. The good thing about him, is that he is willing to give the info to anyone that ask. As many times as these questions come up, Chris is there. Thanks Chris.