I have a 04 X on 37’s, 22” rims, and 6–10” lift. My truck does not stop on a dime. It feels like the brakes are low but I just changed them. Does anyone else have trouble stopping? How can I fix this?

 

Welcome to FTE! Post up pics of your rig! We love pictures!!

On the brakes, what pads/rotors/etc are you running? Have you changed your brake fluid? Are your slide pins clean and lubricated? And what's the condition of your brake lines at the wheel? Folks who run SS braided lines have great results and changing your fluid out is important as well. Everything bled out good?

EDIT: Generally speaking, the X doesn't "Stop on a dime". Can you expand on what you mean by that?

 

My X won’t even antilock brake. As if the load is too heavy or the braking power is not there. I did purchase some high quality pads. I will check the rest of the components you mentioned. Maybe upgrade the lines as flush’s lines as well.

 

Feel like the brakes are really low.

 

The farther your braking surface, tire to ground, gets from the center of the braking device, the less effective the brakes will be.

Calculate the ratio of the stock braking surface to the circumference of the OEM tire. Thats the ratio you need to maintain for the OEM feel, and more importantly, safety.

So, if you increase the OD and braking contact surface (pad to rotor) to the proper ratio, bingo, OEM feel and safety.

 

This is highly subjective. What constitutes good quality? Can you tell us the brand? Did you get them at the local parts store or did you buy online?

I don't understand this statement either. Does the pedal sink too far before engaging the brakes? What happens when you step on them hard?

 

My apologize fir not being more elaborate. When o press the brakes they don’t actually start to engage until about 6-8” after pressing. If I slam on the brakes the truck just won’t stop. It slows down gradually as if the pads are too worn. The brakes wrrr bought at Oreilys auto parts store. Not sure if the brand but they were $60 a set.

 

Thanks for the additional info...

Methinks that @TooManyToys. can likely help you out quite a bit. He's (IMHO) the local brake super expert.

 

Sounds like master cylinder fade, or booster issue. What happens when you bleed all the brakes, does the pedal firm up sooner?

 

@Rmart399 O'Reilly's and high quality brake parts unless special ordered are not high quality.

I have Hawk LTS pads and PowerSlot Cryo Rotors, second set and My 99 F250 will slam you through the windshield if I hammer the brakes. The PowerSlot rotors were $300+ for the pair and the Hawk pads were around $80. Recently I upgraded to PMF stainless lines and O'Reilly's DOT4 fluid and Motorcraft Caliper's up front, didn't feel a change, but the new fluid and lines should help from expanding.

 

I experience the exact same poor braking characteristics. I’ve flushed brake fluid as well as replaced all five lines to stainless steel. I have only checked on caliper as I was replacing the abs sensor and my slide pins were practically siezed. I’m hoping to check the others and find them in the same state and fix it to benefit the poor braking. I’m also running 37’s.

 

To OP.

Part 1. That appears to be too long of a pedal. If you just did the brakes, did you replace calipers? Are all the bleeder screws above the brake hose banjo?

As in like this rear caliper ...




Part 2:

The brake design was developed for 31.7" diameter tires, you installed 37", a rolling radius change from 15.9" to 18.9".

Either way, upping the workload by 17%. Another way of looking at it, reducing the rotor diameter by 17%. You put smaller brakes on the truck with a tire change..

 

Upgrade the hydroboost line from the hydroboost to power steering pump and it will help. Your brakes and power steering are commingled on these trucks. The restrictive fitting on the hydroboost is where the issue is. My truck is not quite as tall but has 35” rubber with stainless lines, new PowerStop pads and rotors and still sucks at stopping. I have a new Motorcraft pump, master cylinder and fluid too. I ordered a custom hose and fitting kit from Sweeting today, he assures me this will help a lot.
Watch this video:

 

I don't mean this in a negative way to you SmackDaddy. If you install that line, I'm sure you will subjectively find it better. Just about everyone, including me, subjectively has an improvement after they spend money and time. Thirty years of listening to how people thought something related to brakes was an improvement, and having the ability to put it on vehicles and measure the results has 98% shown it to be subjective, but not objective once the data is collected.

I saw no proof of anything in that video. However, and I've talked about this elsewhere, but maybe not in this forum. With the Superduty and some other vehicles, hydroboost has an advantage over vacuum boost. Actually, to the point I'd change over to hydroboost if I had a gas powered vehicle.

This is data from I believe the '05+ platform, but the '99 design level was the same. Every vehicle we ran under test I would document the Pedal Effort curves. Since a substantial part of our work was stopping distance and fade performance, understanding the difference between the two vehicle configurations was critical. There were times I had to explain why a certain friction material would not perform best with a specific application, or in our case, motor choice.





Self-explanatory, the top graphs are vacuum assisted and the bottom hydroboost assisted. I presented the graphs in three different layouts in the software so I could use what every I needed for a particular point.

The red circles show the brake pressures during a normal consumer stop, about 200 to 250 psi. The force on the brake pedal at that point is about 15lbs. Soccer Mom territory. And pedal travel is about the same between the two actuation systems, and pedal travel seems to be more of a concern point to many consumers.

50 lbs pedal effort is where you typically can get a Superduty to start skidding a wheel. That depends on the brake temperatures though, a colder brake will take more pressure. The advantage at this force is the hydrobooster gives more assistance, so at the 50lbs pedal effort, you can generate almost 500 psi more hydraulic pressure. That’s a considerable amount of braking increase.

Another way of looking at the data is with a vacuum boosted vehicle you will apply 50lbs pedal force to generate 800 hydraulic psi, while the hydroboosted vehicle only needed 40lbs pedal force to do the same.

The hydroboosted vehicle has a harsher runout or layover, the point where the assistance is no longer given and higher pressures increase as in the manner of a manual brake. However, because of the earlier advantage, at the maximum pedal effort that FMVSS allows, 150lbs, again you can be generated about a 500 psi higher value.

That pressure does require a longer pedal travel, deeper into the floor. But that’s a false issue. If with a trailer with poor brake going down a mountain and you’re overloading the brakes, that extra 500 psi may be an advantage and you don’t mind the longer pedal for the higher pressure. But in God help me moments and your generating 1400psi at 150lbs PE, the max of the vacuum boost, you only need

About 60lbs PE to generate that 1400 hydraulic psi.

The green arrows highlight maximum travel at 150lbs PE.

But again going to the lower pressures, normal stops around 200-250psi, and moderately hard but not panic stops around 500psi, there’s not much of a difference in pedal effort or pedal travel.

Now, putting on tires that change the leverage relationship between the rotor swept center and the tire rolling radius, basically installing a breaker bar on the tires, yeah, you’re going to get into the higher pressures. A 5% change at the OE design level starts to initiate thoughts of a change in rotor diameter and caliper pistons. 10 to 17% by the consumer is, well, interesting. I’ve noticed and documented a higher pedal requirement just by going from 265 to 285 tires on my own vehicle when I had the instrumentation.

As far as going to a braided hose making a different. Looking at it from a hose expansion view, while brake line hoses can make an improvement due to expansion, that dealing with a single stroke, fixed volume change that directly correlates to volume, again of one stroke.

In a continuous flow situation like a PS pump, if under high pressure the hose expands it does so to a point, it doesn’t continually expand like a balloon. Any delay in pressure size is in a few hundredths of a second, then is static.

The amount of fluid that is diverted from the flow stream from the pump, through the HB, then to the steering gear is not a continuous flow; it’s a small volume that’s trapped. The only time you will find fluid coming from the return line out of the hydroboost is upon brake release.

The pressure diversion is based on the need, so a higher pedal effort will block more fluid internally as a person demands high brake pressure. But again, hat’s not volume based, in need of a bigger hose line, it’s a pressure demand on the pump.

So for me what that video implies but does not demonstrate is you can develop higher hydraulic pressures under extreme stopping situations with a conversion to hydroboost. The hose, if that was an improvement the team (friction material supplier/caliper manufacturer/booster manufacturer/Ford) all would have done that during the complaints in the 2000-2001 range where the issue of not freely being able to turn the steering wheel while having the brakes on came to a point where NHTSA got involved, and then backed off once the situation was understood. A hose change would have been a very, very easy solution.

I hope you do feel an improvement, your human like me.

 

You are the brake man, I won’t argue with you about brakes any more than I’d argue with Kovalsky about transmissions BUT...With all the known issues with the 6.0 wouldn’t Ford have made changes to the engine as well or did they just scrap it and introduce the crappy 6.4 instead of continuing the 6.0 with corrective upgrades? There are a ton of simple fixes for problems on these trucks and some updated parts were released but they really didn’t even scratch the surface.
In some of the other videos Sweeting has you can see how quick that truck stops even with the large tires and lift. Are the brake systems different in the Excursions than the Superduty trucks? I can buy just the hose and fitting for about $100, make my own or buy the entire hose and fitting upgrade for $285. I didn’t pull the trigger in it yesterday after I spoke with their shop and read this post...