2004 odyssey has a weird brake pull.

both RF and RR will grab first and then a second later LF and LR will engage.

this makes then van pull to the right for a split second then starighten out.

i replaced frotn pads and the LF caliper at first since i thought the LF was sticking since it wasnt stopping the LF wheel as fast as what the Rf wheel was stopping.

also if i crack open the blleeders, the right side will drip pretty quick. the left side calipers dont drip.

question is really this.. is this van a diagonal system or a one-sided system. i tried looking up where the brake lines run too since i would love to put in a master cylinder, but i am stummped with both right side calipers engaging first then a second later both left side calipers engage.

 

Wrong section.
This is 92-00' civic section.

 

odyssey section isnt "happening" if you know what i mean.

i think i found my issue anyhow. i beleive air is inside the system. i bleed the brakes and the vehicle doesnt dip hard right liek it did. it still pulls while braking then starightens out. but it is a little better. i will try to keep bleeding the system

 

gravity bleed the whole system. Put a bottle in the master cylinder reservoir upside down and then crack all the bleeder screws and let it bleed. I haven't checked out the brake system on a odyssey yet, but I'm assuming if you replaced the calipers and didn't bleed it properly (not saying you didn't, but it happens) then it can cause the lines with no air in them to contact first because there is no air pockets to compress and there will be better pressure in the airless lines... meaning that they will brake better.

 

i will definetly keep trying to get the air out with gravity and vaccumm bledding procedures.

its just weird because the vehcile has 50k miles... and i the vehicle pulling then straightening out happened before i ever touched the brakes. i thought calipers would fix teh issue. no visible leaks and system is holding pressure with a great pedal. i have no idea how i got air in the system before i ever started

 

if bleeding them again doesn't work (remember start at the furthest wheel from the master cylinder and move to the next furthest, it should go RR,LR,RF,LF.) then i would look into replacing the left front brake hose.

 

Is it possibly a proportioning control valve problem?

 

well both right side brakes engage first then the left side engages after one second. (literally one second after...you can count one-one -thousand) bleeding the system did seem to help shorten teh "delay" (now kind of half a second delay) from right side to left. but it is both RF,RR grabbing first then shortly after LF, LR rgabbing second. very distinctive issue and very noticiable especially above 30mph. vehcile dips hard right then straightens out.

suspension is solid frotn and rear. i am spinning the tires manually by hand to rule out suspension issues.

i just wish i knew how front and rear are linked. i was leaning towards master cylinder but i would assume this vehcile (all vehicles actually from 1970 up lol) is a diagonal system so it doesnt explain why the rear calipers are matching the same symptom as the fronts.

i am definetly bleeding them tomorrow afternoon again.. and i will bump this thread for people who are curious.

why do i always get the weird problem vehicles!!! lol

 

If bleeding made it better you need to keep bleeding it.

 

well..air in the system is not what is the problem.

UPDATE:

i pressure bleeded the system...no change.
i vaccuum bleeded the system..no change.
i even did the good ol... "up/down tech pumping brake" routine...no change
i also bleed the proper way.. starting at LF,RF,RR,LR according to alldata...no change.
i went ahead and bleed the ol fashioned "start furthest away from master cylinder" LR,RR,RF,LF... no change

when i thought it was getting better...it was actually not being driven long enough. the first brake engagement while cold feels perfect. but after a couple of stops it will start dipping to the right while braking then straighten out again. this problem is so obvious and quite noticiable. this isnt a slight pull.. the car really pulls hard right where you have to countersteer a little bit. i would say at least a 1 oclock position and steering wheel compenstaes to 11 o clock position.

i did some research and the vehicle is a cross diagonal system so RF and LR are linked and LF and RR are linked. this doesnt explain why both right side calipers are engaging before the left side calipers.

i am ruling out suspesnion due to me physically seeing while in the air the RF caliper engaging before the LF caliper.

i went ahead and switched the brake lines on the master cylinder to rule out a master cylinder problem. vehicle still pulls even with switching the diagonal system.

i went ahead and disbaled the TCS/ABS system by pulling a fuse. the vehicle still dips right while braking and then straightens out. so this rules out electrical portion.

all that is left really is mechanic. seeing that the LF caliper is brand new i can say it isnt a slide issue on the LF. RF caliper is still oem but if that caliper is sticking that wouldnt explain why the vehicle is pulling right while braking.

vehicle has brand new pads and machined rotors from me. so i dont see how new pads could be possibly causing this issue. i will swap them around tomorrow and try lubing all the mechanical parts that i can.

im so stumped on this issue. ..electrical, master cylinder, suspension is all ruled out. it is basically physically impossible for the vehicle to be doing what it is doing. but it is still doing it!!!!

i was thinking a possible internal leaking abs solenoid but it should have switched (pull left while braking) when i switched the master cylinder lines around.

 

Just curious, how did you figure out that both right-side wheels brake earlier that the both left-side wheels?

Don't you now need to switch around brake lines attached to the ABS modulator unit rather than the master cylinder to test whether the modulator may be causing the problem? One possibility is that some foreign material in the modulator unit is impeding flow to the left side calipers.

 

with the vehicle in the air (no tires touching, jacked up) i had another tech go up to about 20 mph or so and then hit the brakes. you can distinctively tell that right side enages first then the left side. night and day. easilly a half a second differnece if not more.

same thing with the rear...spinning them by hand (one tech each wheel going as fast as possible) and another tech inside the car applying brakes. distinctively can see RR engage then LR enagage.

and yes...i have to switch the line after the ABS unit. thanks for pointing that out ron. it just clicked that all i did with switching the lines on the master cylinder is really just checking primary and secondary valves of just the master cylinder and nothing more. i will start there tomorrow if brake line moving around is possible on the ABS unit.

actually i will start at the left front upper portion of the brake hose if possible. (it might connect straight to ABS unit unsure if it is a two piece design) since the LF caliper doesnt drip when opening the bleeder. it blleds fine with pressure/vaccum and pumping but doesnt drip fast at all when just cracking the bleeder.

 

Interesting problem. The diagram below shows brake line routing for ABS in a 96-00 Civic. If the Odyssey is similar, then you should swap brake lines at the ABS modulator that go directly to each of the wheels. If the problem now follows the position in the modulator, then the modulator is likely the culprit. Good luck.

 

that diagram is exactly the same one that alldata faxed me over.

we will see what we find. thanks

 

finally got the change i wanted. i swapped the two front brake hoses and the vehicle pulls the oppostie direction.

bad brake hose is the culprit.

so im assuming LR brake hose is bad as well.

first time a brake hose had such a hard time to diagnois. normally they lock the wheel but i guess the inner brake line can create a flap in either direction. in this case it is restricting going to the wheel but allowing fluid back to the master cylinder.

thanks ron and all the others.

 

Congrats on figuring out this challenging problem. It was an interesting and unexpected solution. What are your thoughts about how two brake hoses went bad? Any TSB?

 

no TSB's that i found regarding a pull while braking.

no real thoughts on how two brake hoses on one side went bad. probaly has to do with not ever changing the brake fluid or possibly the extreme cold weather here in alaska. but still 50k is quite low for these problems. /shrug lol

 

if only you would have listened to me 4 days ago

 

Good call. Have you seen a similar problem previously?

 

yeah..it didnt make sense how both right side wheels were engaging first from a simple solution that you offered of replacing one hose.

i now know both brake hoses are bad.

i was trying to find the common link (one solution) and not two problems and this is where i was messing me up with diagnoisis.

and alldata was showing a different bleeding procedure then what was posted eventhough this vehicle was the best i have ever had in bleeding wise. disconnectin of the abs module and master cylinder along with swapping of the brake hoses (cracking of bleeders for literally 3 seconds) required no bleeding at all which was very odd. i did still bleed but no air came out and pedal was excellent 100 percent of the time.