No need to be posting twice.

It seems like it is nothing to do with your brake job. I'd spend some time searching and reading the forums.

 

It could be a slightly stuck caliper. Caliper that's slickly stuck can easily put enough drag on the rotors to decrease gas mileage measurably.

 

If the brakes are dragging enough to affect your fuel economy, something has to be getting VERY hot. Drive for a while without using the brakes at all. Then stop and feel each wheel.... is anything hot?

Are you sure the emergency brake isn't engaged slightly?

Jack up each wheel.... do they all spin freely?

Paul

 

If the brakes are dragging enough to affect your fuel economy, something has to be getting VERY hot.

Not necessarily. My 05 4runner (and everyone else's 4runner of that generation) had major caliper problems. I replaced them on my 4runner at least 8 times in the 300k miles I owned it. And several times the caliper was dragging. Rotor was slightly hot....but you could touch it without getting burned. Every time I replaced the calipers my gas mileage improved - until I needed to replace them again. I ended up buying them from NAPA which had a lifetime warranty. They started to hate me after my 3rd or 4th replacement.

 

Well that is odd! But a few things first....
Are your MPG comparisons apples to apples? Is your driving route and condition and style the same? Are one of your children taking the car out for drag races at night?OK, JK on that last one...

But I think the first order is to do as @pgoelz suggested...lift and spin to see if they are free.(use proper safety steps in doing so, or use a mech garage lift to check).

You did your brakes yourself, and bled them. which I think is not needed(from what I have read and can make sense of), at least until you decide to replace the brake fluid(which maybe when your changing the brakes).

Would have been great to document your brake change and post in the forum, regardless...

SO, first I just thought you may have missed adding the tension spring that helps keep the pads on the calipers. Then I'm thinking maybe you somehow changed the parking brake calibration that may be depressed and open according to the pedal, but still partly engaged? Not thinking through or really knowing the mechanism of it, so its a guess.
But also as mentioned, if it is causing a MPG drop something is in contact and likely building up heat. You can also take a temperature gun($9-30) and after driving check the temperature of each rotor. This you can do easily and can give you good info. The rear brakes are smaller so they maybe less, but left/right should be even.

Keep us posted....My bet is on the drag racing..jk ...
Well...driving style is often the biggest difference for MPG flux.

 

When people do their own brakes, I doubt most replace everything, and from personal experience i know the caliper pins can be the reason your caliper is sticking (if that's what you determine). I had one brake getting hot and for the life of me, I couldn't figure it out until I removed the caliper pin. I used some emery cloth on it put a little grease on it, and problems solved. Better yet, they are cheap, just put new ones in (don't forget the special grease), and I bet your problem goes away.

 

.... (don't forget the special grease), and I bet your problem goes away.

What is the special grease? I have that small special grey bottle of Anti seeze 133K grease with brush, then a special squeeze bottle of red grease, and then I have a special tube that goes in a tube dispenser of translucent magenta looking greese called HiTemp all purpose greese.....
Which one is specially special?

 

When people do their own brakes, I doubt most replace everything, and from personal experience i know the caliper pins can be the reason your caliper is sticking (if that's what you determine).

I rarely replace caliper pins. However, I do clean them on the wire-brush on my electric grinder. They look good as new. But you're right.. put the pins back in the way they came out and you're asking for trouble. Also remember to grease the pins.

 

If the brakes are dragging, the wheel will get noticeably hot. Be careful laying a hand on it, because if it’s dragging, it can be really hot.

 

David...what yr HL do u have? If all did check out ok, then something else over looked causing lower mpg. :dunno: Any reason to suspect gas?

 

I may stand corrected, but why even open up the hydraulics when doing a brake job? I always just push in the caliper piston with the tool that looks like a caulking gun with 2 metal spreaders. The master will slowly rise to the full mark. the rear calipers on my MR2 were the threaded type that required the round threaded tool with 2 dimples but again pushed (twisted) in. Its a little expensive but you can get OE toyota 08887-80609 brake caliper grease. its a thick white paste. It is the best and proper type. when I do brakes I clean the area where the brake pad tabs on the ends contacts the caliper, and apply the grease in moderation. I also pull the caliper slide pins, clean and grease. The idea is that the brakes will release immediately when you first come off the brakes.

I would say take it all apart, clean it and grease it. get a mity vac or some vacuum bleeder and pull a bottle or 2 of fresh OE Toyota brake fluid through the caliper bleeders. and then bleed the old way with a helper, pump and bleed 3-5 times each caliper to ensure no air is in system.

the only other thing I can question is excessive rotor thickness, but thats really a longshot.

 

this is most special

OE toyota 08887-80609

 

OE toyota 08887-80609

That's the disc brake caliper grease for metal to metal such as the pads & ears. 08887-01206 is the rubber grease. This link is a pretty good one to discuss different brake lubricants. https://forum.ih8mud.com/threads/what-brake-lube-do-you-use.583661/
And here's a SDS from 2012 on the rubber grease which is lithium soap-based glycol grease. http://dolphinmsds.taiamerica.com/MSDSImage/907500/907769.pdf

 

\\\\Probable issues:

- Incorrect rotors installed? May want to consider OEM parts for this.
- Piston/Calipers are seized...may want to consider buy new calipers.
- When pushing piston in, did you forget to open the brake fluid reservoir cap?

 

I have been doing brakes on many different brands and models of cars and trucks for many years. Wondering why not taking the reservoir cap off while pushing the piston back in would result in any problem?

Yes, if the piston of the rotor is out pretty far and fluid had been added to the reservoir as maintenance in between, you may have to take the cap off and remove some extra fluid. But pushing the piston back in and not having excess fluid while leaving the cap on can not result in any condition leading to poor MPG as far as I know. You can't build up pressure inside the reservoir by pushing the fluid back in either because the cap is vented, allowing for release of air.

 

Me and my wife are very frustrated with it based on the fact that you can feel a little bit of the power difference when driving it. The engine still has the full amount of power but you just have to be on the gas more and the Eco Mode is definitely on way less than what it was before.
Any suggestions? David

Obviously replies on what happened after your DIY brake job are logical. But, u said mechanic "couldn't find anything wrong". If all else fails, get your "eng. diagnosed" Might be $ well spent if issue found which affects mpg. Anyhow, good luck on outcome.

 

Thank you for all the replies. I should have been a little more clear on the process, when I change the pads and rotors I just pushed in the caliper piston and had the reservoir cap open for the flu to go back in. The first mechanic I took it to said that nowadays on these cars you're supposed to open the bleeder valve when you're pushing the Piston caliper back in due to all the electronics that monitor that stuff. But after he checked it out he said everything was fine. That mechanic said he raised the car up and checked the front wheels to make sure they were not dragging or rubbing.
When I was doing the front brakes my wife had pushed on and off the e-brake a couple times in a row, will that do anything?
As far as the caliper pins, that's actually what I was addressing every time I took it back apart was I would take him out clean them regrease him because I felt like they're getting stuck. The first mechanic I even brought an extra set of the rubber boots and he said after checking it all out that the caliper pins were completely fine and didn't need any set. There has been no engine code or anything. The second mechanic even pulled out the scanner to double-check as well as redoing the brake job.
As far as the driving Styles, my wife definitely drives a little more aggressive than I do and I would average 23 to 24 mpg and she would average 22. With her currently driving the same type of drives, she is at 17.5. When I drive it the same type of driving and same areas, I am around 19 to 20. There has been absolutely no change mechanically or else before or after the brake job to change or alter anything about the car besides oil changes.
As far as the year it is a 2014. Have never had a problem with the car and have loved it until somehow I f***** this up.
My only other thought now is just if there's something in the computer system that could have changed anything or if it is all mechanical. I was wondering if resetting the ECM would be a bad idea.

Thanks again for all the help sorry for taking so long to reply but I did not see all the replies earlier.

 

When I was doing the front brakes my wife had pushed on and off the e-brake a couple times in a row, will that do anything?

In a perfect world, operating the emergency brakes should not do anything bad. But in the world we live in, the emergency brake cable or mechanism could have stuck partially on. Easy to check.... jack the rear wheels up one at a time and see if they rotate without dragging. Also, checking the rotor temperature after driving is easy. Anything that would affect your MPG would also be getting hot. In my experience, all four wheels should be roughly at the same temperature. If one or more are noticeably hotter, something is dragging.

I do not know exactly how the HL emergency brake works but if it is anything like my Buick Rendezvous, the emergency brake was a drum brake system inside the center of the rear rotors. In other words, a braking system totally independent from the disk system and a possible failure point.

Also, I believe there can be an issue when replacing pads and NOT reconditioning the cylinders where the piston now runs in a different place in the cylinder that might not be totally smooth and could bind. Should be easy to spot by spinning the wheel off the ground, but I guess it could also be intermittent or heat sensitive.

Paul

 

I wish I knew how the park brake works, but that maybe the issue?

Maybe a trip to the dealer might be needed. It doesn't sound like you screwed anything up. At least not anything that cant be fixed. Isolate the parking issue with your wife pressing it, and make sure that has no issues, and then perhaps something in the ECU?

When you drive it you think it feel s like it sticks? Did the mechanics take it for a test drive? Another "trick" you can try that has worked for me is to drive it in an alley way with walls on both sides. This isolates the car from common noisers, and you can really hear if anything is dragging.
Also, maybe the temp laser guage can tell you if one rotor is hotter than the other. These are simple tests you can do yourself before the dealer.

 

So I have to pay $20.50 to $39.04 for the little tube (most are 8 oz) of Toyota grease? Really?
*Genuine Toyota (08887-80609) Brake Caliper Grease.......No data on performance. Where is the white paper on this stuff?

*3M is on the ride for this shake down...They have a Clear Silicone of 8oz for $21.74 Ohhh, what a bargain!...-40F to +400F degrees/ Silicon base, metal to rubber is fine.
*Mission Auto has a "Dielectric silicone grease" for $18.99......stable consistency from -55-570 F / compatible with a variety of materials, including metal, rubber and plastic; prevents voltage leaks around electrical connections
CRC has one under "synthetic Grease 5359 for $11.99...........Contains molybdenum, PTFE and graphite for an extreme temperature range of -30F to 600F
CRC Industries 05353 Brake Caliper Grease $21.99 / 12oz......temperature range of -30F to 600F/ metal to metal contact points and sliding surfaces/
Permatex calls theirs "Ceramic Extreme lube 24125 $14.50......synthetic formula with ceramic solids forming a premium quality brake lubricant/ Effective from -50°F to 3000°F, maintains its lubricating integrity, Resistant to corrosion and contaminants, it will not wash out. For metal-to-metal contact only
*Permatex 80653 Silicone Extreme Brake Parts Lubricant $25.42........-50 degree F to 3000 degree F / Non-melting, 100% silicone based formula, fortified with ceramic solids /
Permatex carrying another lube in a 0.5oz tube!!! of Ultra Disc brake caliper lube for $7.02!
Permatex 80078 Anti-Seize Lubricant $7.57..........Temperature Range: -80°F to 1600°F / A highly refined blend of aluminum, copper, and graphite lubricants that is salt, corrosion, and moisture resistant
Permatex 24110 Ultra Disc Brake Caliper Lube $12.25.......-40°F to 400°F / metal-to-metal contact /

* for possible alternative to the OEM

 

I think what OP means by bleeding the fluid back through the caliper is that he simply pushed the pistons back in and the fluid naturally flowed back up the lines and re-filled the reservoir. There was probably no real "bleeding"/opening of the system taking place. Even if he had added fluid over the years as the pads wore, as ls973800 states above, there's a vent hole in the cap that would vent excess fluid all over the place if the reservoir was too full.

As others have said, raise the vehicle and comparatively spin the wheels. Those that you've done the brakes on should spin the same as those you didn't do, give or take. If you've lost significant mileage due to something to do with the brake job, you're going to see it fairly easily with a wheel spin.

 

To the OP, I'm curious why did you change your rotors and pad so soon? Normally rotor will last much longer than the pads. Do you put a lot of miles on your 2014?

 

Seeing how everybody's talking about touching the thing to see if it's hot, why not just use those infrared thermometer instead. These things are getting pretty cheap. Give you an accurate reading without possible burning.

I should give that a try on mine to see if that's why I have bad mileage too.
But at -10C outside, doubt I can get a good reading. lol

 

I wish I knew how the park brake works, but that maybe the issue?

Most vehicles since the 70's had disc brakes up front and drum rear brakes. The rear brakes also doubled as the parking brake. When Toyota went to 4-wheel disc they decided to keep shoe brakes as the parking brake. Rear brakes on the highlander (and most Toyotas) - rotor is a rotor/drum. Inside the rear rotors are brake shoes used as the parking brake. With this setup those shoes may never need changing (as long as you don't drive with the parking brake on). My 05 4runner had the original shoes when I sold it 305k miles later.

 

SPECIAL GREASE....bull?


Any good high-temperature grease will be fine. Most of the pads I buy come with a little packet of grease.

 

I was hoping you would chime in with such a reply @MikeInNH
Its about $20 for 3.5oz,

Maybe you can take a look at the list above and suggest something based on application, temp and long life of not seizing up, and price being secondary. Not last, but second to performance in comparing the different products.
I was thinking to go with the Auto Mission.
Permetex is claiming up to 3000K temps! While the caliper specific they are the lowest temp at 400F, that is some weird product spec to marketing!?

I was at first thinking highest temp stable would be best, but then I thought about permeability to air and moisture. SO maybe a silicon based would be best.. Hence thinking of the AutoMission Dielectric silicon grease.

 

I was hoping you would chime in with such a reply @MikeInNH
Its about $20 for 3.5oz,

Maybe you can take a look at the list above and suggest something based on application, temp and long life of not seizing up, and price being secondary. Not last, but second to performance in comparing the different products.
I was thinking to go with the Auto Mission.
Permetex is claiming up to 3000K temps! While the caliper specific they are the lowest temp at 400F, that is some weird product spec to marketing!?

I was at first thinking highest temp stable would be best, but then I thought about permeability to air and moisture. SO maybe a silicon based would be best.. Hence thinking of the AutoMission Dielectric silicon grease.

I've never been too picky about the grease I use, and never had a problem either. Most of the time I either use the packet that comes with the brakes, or I have a tub of Amsoil bearing grease that works fine. You not only have to grease the pins, but also the little clips that pads fit into. And the pads I buy usually comes with new clips. I usually reuse the pins, but I clean them on my wire-wheel of my bench grinder. The look new when done.


As for pushing the piston back in....best way is to open the bleeder valve. And I ALWAYS bleed the brakes.


I only replace rotors when needed. I've never had to replace a set under 200k miles. With the exception of my 4runner - calipers usually last past 200k miles also. I'm actually looking to do a complete brake job on my wifes 07 lexus with over 200k miles. I'll replace all 4 calipers and probably the rotors too. I started looking at parts...and I noticed that I can buy just the caliper without the bracket. What a great idea. How many times have you seen a problem with a caliper bracket? I never have. Makes the caliper replacement easier too.

 

Thanks for info and tips. Bvh is correct in the way I pushed the caliper piston back in. On the brake slider pins, I did use a grease that seemed to act sticky instead of a lubricant so that's why I was so obsessed on the slider pins but I cleaned them with qtips and got new rubber dust boots and got silgel? And seemed to work good after that.
I changed the pads and rotors due to scoring of the rotors, my wife had a business that required 6 stops a day as well as taking the kids to school and picking them up 5 days a week. So about 50k miles but lots of short drives in that. Battery already had to be replaced to due to all the starts and stops.
Tomorrow I will jack up the car and check the rears for drag, but how can I tell the front with the CV axles being attached?
As far as if I can tell it's dragging, definitely can tell it's doesn't roll as freely. There's a hill we use to be able to get up to around 85 mph just letting it coast down and now it holds steady at about 70 instead.

Thanks again,
David

 

@Daveid01
Do you mean Sil-glide for the lube? If not, perhaps this is what you were supposed to use, AGS SG8 Lubricant / Sil-Glide

Here is a review about his experience....

"I made the mistake of purchasing a ceramic brake parts lubricant that is not compatible on caliper slide pins with rubber bushings.
High heat, gummed up lubricant, and frozen caliper slide pins! I purchased this after reading some strong reviews and recommendations and the fact that it works well with metal and rubber. Cleaned the slide pins and rubber dust boots, applied this lubricant, and voila... easy movement and fresh looking dust boots. I have a 2010 Corolla with 120,000 miles on it and when I took it in for inspection this past week, the technician asked what I used to make the slide pins move so easily and how the rubber components look so new. I recommended this product to him. I also read a few reviews commenting on it's use for weatherstripping... rubbed this onto the weather stripping around door jambs and trunk and now they don't stick or peel away from the metal."

Another reviewer of another lube called Super Lube 97008 Silicone Lubricating Brake Grease with PTFE, 8 oz Tube, Translucent White

"I used this to lube the disc brake pins when replacing the disc brake pads. Previously someone used Anti-seize in the boot and on the Pin. That stuff is too thick and doesn't move well, It doesn't seize metal, but it doesn't move and float brake pins like the are expected to move.
I clean-out the old stuff out of the rubber boot sleeve using a craft stick and clean rag. Clean the pin.
Apply this silicone brake grease to the pin and bit in the rubber boot. Insert the pin and thoroughly move and turn to coat all internal parts.
Note that this lube is ONLY used internally, inside the rubber boot sleeve for the pin."


I would have bet those pointing to calipers maybe right....BUT, you did have this checked more than once as you mention in your posts....But mechanics might have missed it. Once you rule out the type of grease used was OK? And what parts you may have used for the job(I think you said it was OEM parts?)
Then you can buy the temp gun as I mentioned before, and do more trouble shooting.

How many times have you done a brake job? Assuming it isn't your first, I guess you might have not followed any specific instructions, but perhaps you did? Where did you get those instructions?
FYI, I have done a good share of brake jobs and STILL always look up the specific process for the model, and I try at LEAST 2 sources of material, with one being at least somewhat official, or direct from a manual. Also looking at this forum for info, and its why I am seeing if others know about the different greases...So we can keep this is a useful spot.

 

Phil, last time I got my `special' grease for the caliper pins.....I was at an `Autozone', and they have a small basket with small packets of caliper pin lubricant for $ 2.50 each. The guy said, this is what everyone uses....1 packet for each wheel. I had a huge problem with a sticking pin and whatever generic stuff this was, it solved my problem....I'm betting every parts store has these packets right on the counter.