08 Front brakes under pressure

[ChrisRCNY]

I just picked up an 08 that was used as a police vehicle. I assumed the brakes needed rust removal, but everything is in good shape.

It seems to want to keep the front brakes pressurized. I've not checked the driver's side yet, bit passenger side would only release if I cracked the bleeder.

Starting the engine and pumping the pedal a few times will lock it right back up.

Given the prettyness of the master cylinder, it's possible they replaced it and it's just not releasing. I'm hoping it's the hoses, as they look original.

Does anyone have any other ideas?

 

[ExpeditionAndy]

Welcome to the forum.

Brake hoses have been known to collapse internally causing them to hold pressure. That is probably the first thing I would replace and see if it changes anything.

 

[ChrisRCNY]

That's my current plan. Supposedly the bracket that wraps around the house will rust and constrict the hose a bit. The master cylinder can force fluid in, but it won't return well.

Jacked up driver's side, seems to rotate normally now. Passenger was still locked up tight. I've got both hoses coming in tomorrow, I'll swap them out and pray.

 

[Big Brian]

I would crack the lines going to the fronts at the master to verify the master isnt causing the problem

...which is very doubtful

 

[ExpeditionAndy]

That's my current plan. Supposedly the bracket that wraps around the house will rust and constrict the hose a bit. The master cylinder can force fluid in, but it won't return well.

Jacked up driver's side, seems to rotate normally now. Passenger was still locked up tight. I've got both hoses coming in tomorrow, I'll swap them out and pray.

Do you know the procedure for bleeding the brakes after you change the hoses?

 

[gixer2000]

Welcome to the forum.

Brake hoses have been known to collapse internally causing them to hold pressure. That is probably the first thing I would replace and see if it changes anything.

Bingo!

I just recently had this issue and thought the caliper was stuck. Nope it was a $30 flex hose.

 

[USMCBuckWild]

Flex hoses will definately swell and "collapse" over time. Combination of heat, moisture in fluid and deterioration of fluid; its hard on the rubber liner. Swap the rubber lines (preferably for braided lines with a better quality Teflon or PTFE (polytetrafluoroethylene) equivalent liner) and bleed the entire system. Get all that old fluid replaced with fresh.

 

[Big Brian]

Flex hoses will definately swell and "collapse" over time. Combination of heat, moisture in fluid and deterioration of fluid; its hard on the rubber liner. Swap the rubber lines (preferably for braided lines with a better quality Teflon or PTFE (polytetrafluoroethylene) equivalent liner) and bleed the entire system. Get all that old fluid replaced with fresh.

good points

another common reason they go bad is because people will just let the caliper hang off them when changing the pads and this damages the lines prematurely (it kinks the line where the metal ferrule is crimped on at the hose bracket mount) you should always hang it off a hook made out of a coat hanger or set them on the upper control arm or support them somehow when servicing the pads

the inner lining of the hose can crack and act like a check valve holding fluid in the caliper under pressure. The hose can look fine on the outside but be damaged on the inside

 

[theoldwizard1]

Replacing the brake hose is cheap and easy (Motorcraft left BRHF131, Motorcraft right BRHF66) , but I don't think this is the real problem. Still worth doing. Biggest problem with replacing the brake hose is rust on the fitting on the both ends of the hose AND on the bleeder screw. Likely these will all need a bit of heat from a propane torch.

When replacing the "core" brake parts, I always stay with "top of the line" NAME BRAND parts, like Wagner or Raybestos.

If it was me, along with the hose, I would purchase and install rebuilt caliper, pads and mounting hardware (Raybestos Police left RC11948SV, Raybestos Police RC11945SVP). I don't know if this includes the slider pins, but I would replace them also (Raybestos H5089) .

If the pads have been sticking for awhile, you will probably need a new rotor (Raybestos Police 680508P).

 

[ExpeditionAndy]

Replacing the brake hose is cheap and easy (Motorcraft left BRHF131, Motorcraft right BRHF66) , but I don't think this is the real problem. Still worth doing. Biggest problem with replacing the brake hose is rust on the fitting on the both ends of the hose AND on the bleeder screw. Likely these will all need a bit of heat from a propane torch.

When replacing the "core" brake parts, I always stay with "top of the line" NAME BRAND parts, like Wagner or Raybestos.

If it was me, along with the hose, I would purchase and install rebuilt caliper, pads and mounting hardware (Raybestos Police left RC11948SV, Raybestos Police RC11945SVP). I don't know if this includes the slider pins, but I would replace them also (Raybestos H5089) .

If the pads have been sticking for awhile, you will probably need a new rotor (Raybestos Police 680508P).

That's what I did last summer to my old 05 one of the caliper was sticking so I replaced calipers, pads, rotors, and hoses. I did front and rear because they were original and I got the friends and family discount from my friend and it was way cheaper than anywhere else.

 

[Flippingroc]

My expy does this sometimes after a hard braking. Im going to investigate a bit further because occasionally i'll get some noise, serious vibration and engine drag- almost as if the front left brake is still on. Other times its fine. I was initially thinking wheel bearing, but truck doesn't pull either way and more so the advancetrac light comes on whenever I've need wheel bearings ironically enough

 

[USMCBuckWild]

My expy does this sometimes after a hard braking. Im going to investigate a bit further because occasionally i'll get some noise, serious vibration and engine drag- almost as if the front left brake is still on. Other times its fine. I was initially thinking wheel bearing, but truck doesn't pull either way and more so the advancetrac light comes on whenever I've need wheel bearings ironically enough

One of the key indicators is if the truck (or the steering wheel) pulls to a specific side while braking; sometimes only when braking hard.

 

[Flippingroc]

shoulda mentioned that, I have noticed a slight pull to the right- suggesting the left is a bit weaker

 

[theoldwizard1]

The quickest way to check for a caliper problem is to check the wear on all 4 pads. They should be close to equal wear. If one pad has excessive wear, that caliper is sticking.

 

[Randall Hall]

I too have a retired police 2008 Expedition XLT SSV with 105,000 miles when I got it. When I bought it, the front breaks were stuck and I had to have it towed from the dealer straight to the shop (I took a gamble because it was valued at $10,500 but paid $5,200 for it). They replaced the break hoses and the shoes and that was all that was needed to fix the breaks. They were just old and dry rotted.

So far my "great deal" gamble has led me to have to fix or replace the starter, steering pump, smart Junction box, Two TPMS monitors and a TPMS mount, three O2 sensors, a camshaft position sensor, and a rear strut (but did both rear), a front turn signal bulb, and fixed every single door seal. I still have to replace the transmission pan gasket as its leaking and I now have brand new check engine light that came on last night. I think I am now invested in what its worth so nothing else can break....

 

[theoldwizard1]

So far my "great deal" gamble has led me to have to fix or replace the starter, steering pump, smart Junction box, Two TPMS monitors and a TPMS mount, three O2 sensors, a camshaft position sensor, and a rear strut (but did both rear), a front turn signal bulb, and fixed every single door seal. I still have to replace the transmission pan gasket as its leaking and I now have brand new check engine light that came on last night. I think I am now invested in what its worth so nothing else can break....

While that is a long list of repairs and I am sure they cost a lot of $$$, for a vehicle that age, only the Smart Junction Box and door seals are really out of the ordinary. Transmission pan gasket is due to a prior sloppy repair.

I have to admit, that I am blessed with the mechanical ability to have diagnosed and handled most of those (except SJB and TPMS issues).

Not sure how long it has been in your hands, but KBB say it is worth about $7,000 today.

 

[ChrisRCNY]

Well, I found the problem. Front hoses were compressed by rust on the inside of the bracket. I used a grinder to weaken the bracket enough to let me pry it open and remove the hose. Instant freed brakes.

I'll be doing the hoses when I have cash.

Bleeder screw was in great shape, squirted fluid across the underside of the truck the first time I loosened it. The hard line might unscrew politely. Might.

 

[ExpeditionAndy]

Well, I found the problem. Front hoses were compressed by rust on the inside of the bracket. I used a grinder to weaken the bracket enough to let me pry it open and remove the hose. Instant freed brakes.

I'll be doing the hoses when I have cash.

Bleeder screw was in great shape, squirted fluid across the underside of the truck the first time I loosened it. The hard line might unscrew politely. Might.

Chris that's great news. It is so good when you can finally figure it out. Keep an eye on those hoses. Hoses that have been compressed like that are suspect and probably on their way out. You don't want one to blow in an emergency situation.

 

[theoldwizard1]

The hard line might unscrew politely. Might.

Start spraying it daily with penetrating oil. Make sure you use a "line" wrench to hold the fitting that stays on the line. A regular open end wrench will round off the brass hex. Once the line is off make sure that fitting spins freely before installing the new hose.

 

[Flippingroc]

UPDATE: As I don't like to do my own work, brought my truck in with advise from you guys. Although I was very low on pad and rotor life which I had already known (10-20% left) the sticking issue was getting bad enough to where it was effecting traction control functions- it would basically bring the vehicle to a stop. Ford did the pads and rotors as I instructed and also found that my drivers side brake hose had collapsed/deteriorated. I'm back to normal now!