Toyota RAV4 Forums banner
1 - 20 of 98 Posts

·
Registered
Joined
·
91 Posts
Discussion Starter · #1 · (Edited)
2 years ago I bough a second hand Toyota RAV4 2013 LE FWD. When I bough it, the previous owner installed new rotors and brake pads in the front wheels upon my request and practically overflowed the master cylinder with DOT3. It was way above the max indicating line. Soon after I installed new rotors and brake pads in the rear wheels. The brakes felt amazing for more than a year but lately I've been noticing I have to push the pedal deep to be able to get the same effect. I said well, the DOT3 is probably due for replacement and over time it absorbed water. I changed the DOT3 with OEM DOT3 fluid and the fluid I was replacing looked like new. At no moment I saw any rust particles or color change respect to the new fluid. I noticed that the 2 drain valves for the rear calipers had been replaced by new ones. After the change was done I filled the master cylinder to the max indicating line and tested the brakes. They still feel week compared to when the car was bought. I tried braking from 100 km/h to full stop but without stepping on the brake to the max and the car would take 40 to 50 m before stopping. I don't know if this is normal. At no point the tires or brakes emitted any noise. It was a perfectly silent stop. I inspected the calipers for leaks without disassembling them but I couldn't find any. I notice the rotor on the rear right wheel (longest brake line) doesn't show a uniform smooth wear like the others (see larger picture compared to the 2 smaller). Could this mean that this wheel is not braking properly? Its shows a couple of circular grooves. I'm aware that as brake pads begin to wear the brakes in RAV4 could begin feeling spongy (according to some posts I've read in this forum) but I miss the previous braking strength! Also if the car is OFF the brakes are super hard, almost impossible to press, when started in parking the brakes become soft and in forward they turn even softer than in parking (but this could be just an idea of mine)

I would like to ask:
  1. How can I check my master cylinder is not leaking internally.
  2. How can I check my booster is still good
  3. Is there anything else like ABS, etc that may need to be checked
  4. And if it was how dangerous is it not to replace it right away.
  5. Also what could be the consequences of filling my master cylinder above the max indicating line to see if I can regain some brake strength
169953
169954
169955
 

·
Registered
Car: red, with some black trim
Joined
·
135 Posts
sometimes air can get in while bleeding if the reservoir gets just a shade too low. This may require bleeding all 4 calipers again.

also air can get in around the outside of the nipple thread. Install any new nipples with ceramic brake grease on the threads, this will make that joint fluid tight at the low pressure used for bleeding.

Also never shake the fluid bottle, don't let it splash into the reservoir, any bubbles in the reservoir will take ages to dissipate so if you see any, take a coffee break until they are gone.
 

·
Registered
Joined
·
91 Posts
Discussion Starter · #3 ·
sometimes air can get in while bleeding if the reservoir gets just a shade too low. This may require bleeding all 4 calipers again.

also air can get in around the outside of the nipple thread. Install any new nipples with ceramic brake grease on the threads, this will make that joint fluid tight at the low pressure used for bleeding.

Also never shake the fluid bottle, don't let it splash into the reservoir, any bubbles in the reservoir will take ages to dissipate so if you see any, take a coffee break until they are gone.
I made sure no air could get in. I didn't use needles. I used a transparent hose (similar to the ones in aquariums and hospitals) and I fit it extremely extremely tight around the bleeding valves. I'm telling you that the hose would need to expand to double its original size to fit and had to be installed with pliers. Then I fit a zip tie on the bottom of it. Furthermore every 3-4 pumps I would refill the master cylinder. After the job was done pulling the hose out of the closed bleeding valves was extremely difficult as well
 

·
Registered
Joined
·
260 Posts
I'm not a pro at this, but isn't there something about bleeding the ABS system? Isn't there a special bleed-cycle you run through TechStream?

Perhaps you have air in the system that normal pedal pushing cannot get out?

Again - not a pro - but the fact the pedal is hard when the car is not running makes me wonder if you've got some kind of booster issue?
 

·
Registered
Joined
·
91 Posts
Discussion Starter · #5 ·
I'm not a pro at this, but isn't there something about bleeding the ABS system? Isn't there a special bleed-cycle you run through TechStream?

Perhaps you have air in the system that normal pedal pushing cannot get out?

Again - not a pro - but the fact the pedal is hard when the car is not running makes me wonder if you've got some kind of booster issue?
I have seen a few videos of people bleeding cars with ABS systems and nobody did anything weird. What is TechStream? Yes, I saw a video of Scotty Kilmer mentioning booster problems if brake pedal only becomes soft after starting. Do you know if there is another way to troubleshoot the booster?
 

·
Registered
Joined
·
260 Posts
TechStream is the official Toyota software that communicates to the ECU's and provides analysis and diagnostics. "Hacked" copies are availlable one eBay and the like. There is a special ABS bleed function that repeatedly energizes the pressure solenoids to remove any air trapped within the ABS block - occasionally air can be trapped within the ABS unit and conventional pedal bleeding cannot remove it.

As for the booster, sorry - just dangerous enough to know that's a potential issue... Never had to test one myself, but I'm sure Google has a few ideas.
 

·
Registered
Joined
·
91 Posts
Discussion Starter · #7 ·
TechStream is the official Toyota software that communicates to the ECU's and provides analysis and diagnostics. "Hacked" copies are availlable one eBay and the like. There is a special ABS bleed function that repeatedly energizes the pressure solenoids to remove any air trapped within the ABS block - occasionally air can be trapped within the ABS unit and conventional pedal bleeding cannot remove it.

As for the booster, sorry - just dangerous enough to know that's a potential issue... Never had to test one myself, but I'm sure Google has a few ideas.
Is there a way to connect a device through OBD2 and estimate if there is air trapped within the ABS block?
 

·
Registered
2010 2.0 VVTi RAV 4
Joined
·
1,175 Posts
To test if there is any air in the system, when stationary, engine off, I would pump the brake pedal three times slowly, and then hold it down.

If it sinks after this, the master is leaking. If it firms up considerably, then you have compressed the air in the system where it is now working. Go for a drive, and see what happens. Try this again and see what happens.

Looking at you pictures, especially the first one, I think you have sticking calipers or guide pins. I would suggest you do a full brake lube service as a minimum. I also use a pressure bleed device to bleed the bakes, if you think you have air, may be try that. If not, a fancy scan tool can perform a ABS bleed. You may need a mechanic or shop to do that.
 

·
Registered
Joined
·
260 Posts
No, I don't think there is any way to determine air in the system by sensors. And I agree that most of the time bleeding the ABS doesn't seem to be an issue. I'm just trying to think of the less common things, sense it sounds like you've been looking at this problem for a while...

Edit - I also agree about the sticking calipers that Bigphil555 pointed out. That wheel needs a disassembly, cleaning and lube at a minimum.
 

·
Registered
Joined
·
239 Posts
Is there a way to connect a device through OBD2 and estimate if there is air trapped within the ABS block?
Your first picture clearly show that the caliber is not working. Replace that caliber before continuing. 40 years of mechanics and every time I've seen a rotor like this, the caliber is probably has rust internal, preventing the piston from traveling freely.

If you put new pads on and just compress the piston, the caliber will usually work for a while, but will eventually do the same thing.

Get a brake bleed kit that lets you pump the brake fluid from the bottom up. This forces air in the ABS to go up to the master cylinder.

I would also convert over to DOT4. It will stiffen the pedal a little and has higher boiling point, important if you have long downhill runs with a lot of steady braking.

Good luck.

Have a good day.

PS. Your pedal issue is more then likely from this issue. If the rotor is shiny on the other side, then you simply have stuck guide pins.

Check pins and if not stuck, then replace the caliber and simply bleed that caliber when you replace it. As long as you haven't let the master cylinder run out of brake fluid, then you don't have to worry about air in the system.
 
  • Like
Reactions: BoomerNJ

·
Registered
Joined
·
91 Posts
Discussion Starter · #11 ·
To test if there is any air in the system, when stationary, engine off, I would pump the brake pedal three times slowly, and then hold it down.

If it sinks after this, the master is leaking. If it firms up considerably, then you have compressed the air in the system where it is now working. Go for a drive, and see what happens. Try this again and see what happens.

Looking at you pictures, especially the first one, I think you have sticking calipers or guide pins. I would suggest you do a full brake lube service as a minimum. I also use a pressure bleed device to bleed the bakes, if you think you have air, may be try that. If not, a fancy scan tool can perform a ABS bleed. You may need a mechanic or shop to do that.
When my engine is off the brake pedal doesn't move at all. It's rock solid. A checked that about 10 seconds after I turn off the car the brake pedal won't move anymore.

Thank you for commenting about the photo. I didn't know that brakes required lubrication but now I have found this video with tips
 

·
Registered
Joined
·
91 Posts
Discussion Starter · #12 ·
No, I don't think there is any way to determine air in the system by sensors. And I agree that most of the time bleeding the ABS doesn't seem to be an issue. I'm just trying to think of the less common things, sense it sounds like you've been looking at this problem for a while...

Edit - I also agree about the sticking calipers that Bigphil555 pointed out. That wheel needs a disassembly, cleaning and lube at a minimum.
Yes I will disassembly, cleaning and lube it. What do you mean at minimum?
 

·
Registered
2010 2.0 VVTi RAV 4
Joined
·
1,175 Posts
As a minimum, do the brake lube service - guide pins, pad ears and contact points.

TBH, you may be looking at new rotors and pads and as above, the caliper may need to be replaced or serviced.

Sounds like you do not have air in the system, but sticking brakes
 

·
Registered
Joined
·
91 Posts
Discussion Starter · #14 · (Edited)
Your first picture clearly show that the caliber is not working. Replace that caliber before continuing. 40 years of mechanics and every time I've seen a rotor like this, the caliber is probably has rust internal, preventing the piston from traveling freely.

If you put new pads on and just compress the piston, the caliber will usually work for a while, but will eventually do the same thing.

Get a brake bleed kit that lets you pump the brake fluid from the bottom up. This forces air in the ABS to go up to the master cylinder.

I would also convert over to DOT4. It will stiffen the pedal a little and has higher boiling point, important if you have long downhill runs with a lot of steady braking.

Good luck.

Have a good day.

PS. Your pedal issue is more then likely from this issue. If the rotor is shiny on the other side, then you simply have stuck guide pins.

Check pins and if not stuck, then replace the caliber and simply bleed that caliber when you replace it. As long as you haven't let the master cylinder run out of brake fluid, then you don't have to worry about air in the system.
I can confirm that my calipers have rust inside. I would say all of them have. I mean in the piston that is supposed to compress the pads. Are calipers something you change in pairs? Lets say both rear wheels at the same time? Is this something that is worth considering after market or should I stick with OEM like if I were to replace the master cylinder? I will check and lube this to see if there's anything stuck

Do you have any thoughts about questions 4 and 5?

About the DOT4 I know it is compatible with DOT3 but I rather stay with the OEM product, which is DOT3
 

·
Registered
Joined
·
91 Posts
Discussion Starter · #15 ·
As a minimum, do the brake lube service - guide pins, pad ears and contact points.

TBH, you may be looking at new rotors and pads and as above, the caliper may need to be replaced or serviced.

Sounds like you do not have air in the system, but sticking brakes
I just installed new rotors and pads on the rear wheels 2 years ago. And this problem is happening on the rear right wheel. I will definitely do the brake service. Do you replace calipers in pairs? Could a sticky brake cause brake pedal weakness?
 

·
Registered
2010 2.0 VVTi RAV 4
Joined
·
1,175 Posts
@vmmf , brake weakness could easily be caused by sticking guide pins and calipers. You need to overcome what could be huge resistance just to start the braking process. I am not saying it is the answer, but it very well could be.

Replacing calipers in pairs is a mute point. If the other one is good, then no. However, looking at yours, it is highly possible that both are in need of replacement. If it were me, I would do both to be safe for you and other road users - it is your call though. You can ruin pads and rotors very quickly if they are not functioning properly, and I am sorry to say this, but I think both may need changing - again for safety. You may find a shop that could turn the rotors for you, I just do not know the cost difference in Canada.

For fluid, you are perfectly safe to go up the numbers, ie 3 to 4 or even 5.1, but never downgrade

Hope this helps
 

·
Registered
2010 2.0 VVTi RAV 4
Joined
·
1,175 Posts
For a video, look at SMA and Eric O on Youtube - his videos are excellent - it will give you detailed guidance
 

·
Registered
Joined
·
91 Posts
Discussion Starter · #19 · (Edited)
@vmmf , brake weakness could easily be caused by sticking guide pins and calipers. You need to overcome what could be huge resistance just to start the braking process. I am not saying it is the answer, but it very well could be.

Replacing calipers in pairs is a mute point. If the other one is good, then no. However, looking at yours, it is highly possible that both are in need of replacement. If it were me, I would do both to be safe for you and other road users - it is your call though. You can ruin pads and rotors very quickly if they are not functioning properly, and I am sorry to say this, but I think both may need changing - again for safety. You may find a shop that could turn the rotors for you, I just do not know the cost difference in Canada.

For fluid, you are perfectly safe to go up the numbers, ie 3 to 4 or even 5.1, but never downgrade

Hope this helps
If I need to overcome what could be huge resistance just to start the braking process. Wouldn't that make pressing the brake pedal very hard? I'm make case it is the opposite. The brake pedal is very easy to press while running

Are calipers something that is worth considering after market or should I stick with OEM like if I were to replace the master cylinder? Do calipers change depending on what wheel they need to be installed on or is it one part fits all?

The price of turning rotors is almost the same as buying new ones. Why do you think my rotors are bad? I'm learning here

Do you have any thoughts about questions 4 and 5?

I think I found the OEM part here: 2013 Toyota RAV4 Caliper. Brake. Disc - 478500R030 | Toyota Parts Direct, London ON
 

·
Registered
Joined
·
260 Posts
The price of turning rotors is almost the same as buying new ones. Why do you think my rotors are bad?
In the "old days", turning rotors was a common, cost effective practice. These days, no mechanic I've spoken to has recommended it - they claim that modern rotors are often thinner to begin with, and the depth of material that needs to be removed results in the rotor ending up much too thin to be worthwhile. I can't comment on how much rotor thicknesses has changed, but I know I've inquired several times about resurfacing and the answer has been the same at multiple repair centers.

As for why your appear to be bad, I think the maximum variation from "flat" on the pad surface area permitted is only around 0.015", and yours appear to be beyond that.
 
1 - 20 of 98 Posts
Top