# 1994 Ford Explorer XL 4WD - What could make BOTH front calipers not release? **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** ford\ **Created:** [July 28, 2023, 12:44am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949 "2023-07-28T00:44:22Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![gruntsparkles](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@gruntsparkles](https://community.cartalk.com/u/gruntsparkles)\ **Post date:** [July 28, 2023, 12:44am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/1 "2023-07-28T00:44:22Z")
Okay, so this is a used car that I bought a few years back and had an obvious brake problem, turned out the front right caliper was definitely not releasing. Replaced the rotors, bearings, calipers, pads, and brake hoses inside the wheel well, on both sides. I have not used the car much since then because problems have persisted. Here are the symptoms I’m seeing. When I get up to 45+ (esp. going downhill), I start getting wobble in the steering wheel. After driving for 10 or 15 minutes, I usually (but not always) start to get a wheel/rotational squeak that goes away when I brake. The front brakes seem too hot: just got home from a short drive and both the front rotors were at 400+ degrees (F). I’ve posted about some of this before, but I think I’m describing the situation more clearly now. To me it seems like both front calipers are keeping too much pressure on the rotors. What could do that? I looked for a pinched brake line and didn’t find anything. Power brake booster? Hydraulic control unit? Oh I should mention that I took out the fuse for the ABS a while back and it made no difference. And the rear brakes seem okay to me, that is they are not getting too hot or otherwise attracting my attention. Thanks for reading. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [July 28, 2023, 12:50am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/2 "2023-07-28T00:50:39Z")
The rubber hoses to the calipers. Over time, these hoses fail internally. And when this happens, the hoses can act like check valves, This means when you apply the brakes, the hydraulic pressure forces the pistons out. But when you release the brakes the hoses prevent that hydraulic pressure from being released. So the brakes stay applied. Tester ---
**Author:** ![gruntsparkles](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@gruntsparkles](https://community.cartalk.com/u/gruntsparkles)\ **Post date:** [July 28, 2023, 1:05am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/3 "2023-07-28T01:05:32Z")
Brake hoses to calipers were replaced in both (left and right) wheel wells. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [July 28, 2023, 1:23am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/4 "2023-07-28T01:23:48Z")
Guide pins etc lubed with brake grease? ![image](https://global.discourse-cdn.com/cartalk/original/3X/4/6/46170f9b643309a2ff71a80bcc5ddd049c1bfbb8.jpeg) Tester ---
**Author:** ![gruntsparkles](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@gruntsparkles](https://community.cartalk.com/u/gruntsparkles)\ **Post date:** [July 28, 2023, 1:28am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/5 "2023-07-28T01:28:40Z")
Yes, guide pins were lubed, then lubed again just in case. I’ve had the system apart a few times 🙂 ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [July 28, 2023, 1:32am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/6 "2023-07-28T01:32:30Z")
Bad master cylinder. ---
**Author:** ![gruntsparkles](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@gruntsparkles](https://community.cartalk.com/u/gruntsparkles)\ **Post date:** [July 28, 2023, 1:35am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/7 "2023-07-28T01:35:22Z")
For what it’s worth, the master cylinder looks new. I suspect the previous owner(s) were troubleshooting this situation too. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [July 28, 2023, 1:51am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/8 "2023-07-28T01:51:12Z")
If the calipers are original, then caliper piston pitting may be preventing the calipers from releasing. > **[Sticking Brake Caliper Piston - Free ASE Study Guides](https://www.freeasestudyguides.com/brakes-sticking-brake-caliper.html)** > > Environmental contamination and rust result in sticking brake caliper pistons. Water leaks past the caliper piston's protective boot. It's often easier and more cost-effective to replace a sticking or seized brake caliper. Tester ---
**Author:** ![gruntsparkles](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@gruntsparkles](https://community.cartalk.com/u/gruntsparkles)\ **Post date:** [July 28, 2023, 1:56am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/9 "2023-07-28T01:56:43Z")
Both calipers have been replaced with new ones. (I did mention this in the OP.) ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [July 28, 2023, 2:20am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/10 "2023-07-28T02:20:24Z")
Then, I’d start looking at the ABS system. > **[Symptoms of a Bad or Failing ABS Control Module | YourMechanic Advice](https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-abs-control-module)** > > Common signs include an unresponsive brake pedal, the ABS Light coming on, and brakes locking up. Tester ---
**Author:** ![gruntsparkles](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@gruntsparkles](https://community.cartalk.com/u/gruntsparkles)\ **Post date:** [July 28, 2023, 2:47am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/11 "2023-07-28T02:47:48Z")
Sounds reasonable. I did pull the fuse for ABS, but I could also unplug its wire harness. I’ve wondered if some valve in the ABS or hydralic control unit got stuck. Of if maybe there was some other malfunction/contamination in there. Causing it to act like a check valve, as you mentioned with the hoses above. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [July 28, 2023, 4:54am UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/12 "2023-07-28T04:54:02Z")
After driving for 15 minutes, jack up the front of the vehicle. Do you feel heavy drag when rotating the front wheels? Loosen the master cylinder mounting nuts and pull the master 1/4" away from the brake booster to see if the front brakes release. ---
**Author:** ![gruntsparkles](https://avatars.discourse-cdn.com/v4/letter/g/8edcca/32.png) [@gruntsparkles](https://community.cartalk.com/u/gruntsparkles)\ **Post date:** [July 28, 2023, 3:39pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/13 "2023-07-28T15:39:41Z")
Great idea! Looking forward to trying it when I get the chance. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [July 28, 2023, 9:49pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/14 "2023-07-28T21:49:48Z")
Take a look at the MC. Does it have rubber brake lines between the MC and the proportioning valve? Not a common configuration these days, but my older Ford truck is configured like that. If your Explorer is like that, one of those rubber hoses could be the problem, would likely affect both front brakes. My guess however matches up to Nevada’s above, not enough play between brake pedal and brake MC, causes the brakes to be applied slightly all the time. If so, ask your shop if it might be possible to fix that problem without replacing the MC. ---
**Author:** ![keith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/keith/32/5518_2.png) [@keith](https://community.cartalk.com/u/keith)\ **Post date:** [July 28, 2023, 9:56pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/15 "2023-07-28T21:56:36Z")
You mentioned the bearings in the OP. I don’t believe these are replaceable by themselves, the hub assembly has to be replaced. Did you do that? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [July 28, 2023, 9:59pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/16 "2023-07-28T21:59:42Z")
> **[1994 FORD EXPLORER 4.0L V6 Wheel Bearing | RockAuto](https://www.rockauto.com/en/catalog/ford,1994,explorer,4.0l+v6,1119631,brake+&+wheel+hub,wheel+bearing,1672)** > > RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog. Tester ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [July 28, 2023, 10:06pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/17 "2023-07-28T22:06:48Z")
> **[1994 FORD EXPLORER 4.0L V6 Rotor | RockAuto](https://www.rockauto.com/en/catalog/ford,1994,explorer,4.0l+v6,1119631,brake+&+wheel+hub,rotor,1896)** > > RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [July 28, 2023, 10:20pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/18 "2023-07-28T22:20:34Z")
The front brake drums on my Ford truck could be called the hub, b/c they contain both inner and outer wheel bearing races. There are two tapered wheel bearings that are separate parts, easily removed from the drum. According to Tester’s link above, seems some 94 Explorers are configured w/separate tapered wheel bearings, some are configured with the type of wheel bearing that is pressed into the hub, sealed wheel bearings like used on bicycles. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [July 28, 2023, 10:42pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/19 "2023-07-28T22:42:38Z")
> [@George\_San\_Jose1](#): > > seems some 94 Explorers are configured w/separate tapered wheel bearings Yes, rear wheel drive Explorers > [@George\_San\_Jose1](#): > > some are configured with the type of wheel bearing that is pressed into the hub All wheel drive Explorers ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [July 28, 2023, 10:45pm UTC](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949/20 "2023-07-28T22:45:34Z")
Just curious, OP says in top post title their Explorer is XL 4WD. Is that the same as what you refer to as all wheel drive? So it uses the type of wheel bearing that is pressed into the hub, which I’m assuming is also the disc? [Next page](https://community.cartalk.com/t/1994-ford-explorer-xl-4wd-what-could-make-both-front-calipers-not-release/191949.md?page=2)