tonezilla

i got a 94 accord lx with no abs, with discs in the front and drums in the rear . i was bleeding the brakes today and i was wondering, do i need to release the hand brake when i am bleeding the rears ? because no brake fluid came out of my rears when i tried to bleed them, but it bled fine when i did the fronts . is there something that i am missing ?

edit: i also bled the brakes using the order in the haynes manual, which is rear right, front left, rear left, and front right .


Modified by tonezilla at 5:20 PM 1/7/2006

P_Adams

The Hand brake has no bearing on the bleeding of the brake system.
I am concerned of your observation that you got no fluid out of the rears (however). It is SUPPOSED to flow just as much fluid as the fronts. It's possible the bleeder screws have rusted shut, but you should still see some fluid seeping past the threads when you loosen it.
A question:
Does the brake pedal remain firm even when you open the bleeder screws?

P

tonezilla

yes, the brake pedal was still firm after i opened the rear bleeder screws . is this bad ? does is take awhile for the fluid to come out when bleeding the rears, or is it supposed to come out as soon as i open it ?



Modified by tonezilla at 3:15 PM 1/5/2006

BLKFLSH

It should work the same way that the front does. The bleed bolt is probably clogged up. Maybe if you take them all the way out, you can clean them out with something. Then put them back in, and try bleeding again.

P_Adams

You should be taking a shower in brake fluid if your assistant is pressing down on the brake pedal while you open the screw. There should be no delay with regards to the fluid moving.

Hopefully it's just a clogged bleeder screw issue. If not, anticipate picking up a new combination valve.

P

tonezilla

whats a combination valve ? is this the same as the proportioning valve ? what do i need to do if i needed to buy a new one ?


Modified by tonezilla at 4:02 PM 1/5/2006

P_Adams

A combination valve is often referred to as a proportioning valve, but it also (depending on manufacturer) sometimes combines the mechanism by which the brake hydraulic warning light comes on.
In effect, the system is divided into two separate brake systems and then the fluid's distributed thus:
the L/F and R/R wheels
and
the R/F and L/R wheels
Within the Combination valve is a bore which links the two separate systems. In this bore (perfectly centered) is a circular piston with a groove machined around it's middle. A plunger from the brake warning switch sits in this groove.
There are incidences where one side of the hydraulic system suffers a catastrophic failure, and because of unequal system pressure side/side, the piston moves off center; turning on the light and sometimes blocking flow to the damaged side.

let me look around a bit and give you a better idea what you MAY be up against. There may be a procedure which MIGHT recenter the piston and re-establish flow (if that's what we're seeing here)

P

tonezilla

ok thanks . ill be waiting for your answer . crossing my fingers that it is nothing serious .

P_Adams

In the mean time, have someone with an educated foot press down on the brake pedal (lightly) while you crack the rear bleeder screw. You should see brake fluid leaking past the screw threads long before it falls out of the cylinder (Hopefully)
***Do NOT allow him/her to release the pedal until you re tighten the bleeder screw**

P

The valve in question (I believe) is #5 in the linked illustration, but I'm hoping it doesn't come to that
http://www.hondaautomotivepart...81%29


Modified by P_Adams at 1:41 AM 1/6/2006

iam7head

you might want to pick up a "speed bleeder" valve while you at it, they cost around 7.99 per piece.

they are a one way check valve, which makes brake bleeding much more enjoyable. a very useful tool if you track the car often.

tonezilla

well, i had someone stepped on the brake pedal lightly, and released the bleeder screw, but no brake fluid came out . so while she was still holding the pedal down, i unscrewed the whole bleeder screw out and it had fluid in it, but not enough that it poured out of the hole . so is it possibly the combination valve ?

i posted a thread a few weeks ago where the problem all started . i was driving and all of a sudden my pedal was depressed all the way to the ground . no brake light came on, but as soon as i got home, the brake master cylinder was empty . also, my front driver side brake line was damp so i thought there was a leak in it . i replaced the brake line and bleeded the brakes, but was the combination valve the problem from the very beginning ? so if the combination valve is the problem, how did the valve cause the problem ? you explained it earlier, but what would cause it to malfunction like that ?

i also did a search, and i was wondering if the combination valve are compatible with other ones ? or could i only use the valve from a 94 accord lx with no abs ? where is it located on the car ? and is it just a simple remove and install, or would i need to install it and bring it somewhere to get it calibrated ?


Modified by tonezilla at 10:34 PM 1/5/2006

Honda-Master

try sticking a paper clip in the rear wheel cylinder bleeder hole , with the bleeder screw removed of course ,, it could be plugged up..

tonezilla

bump, so is the cause of my problem the combination valve after all ?

P_Adams

One last thing to check. Do the rear wheel brakes apply when pushing down on the brake pedal?
__If they do, you're getting pressure to the rear brakes. (and it is NOT likely the Combination valve). The problem most likely resides in the rear wheel cylinders (rust or crud for age).
__If they do not, it's looking more and more like the C/Valve

P

tonezilla

how do i check this ? i released the hand brake, and turned all the rotors and they spun freely, and then i asked someone to step down on the brakes, and then i turned the rotors again and they didnt turn at all . it seems to be working alright . am i doing this right ?

BLKFLSH

Like P said, If the rear brakes work, it would be either the wheel cylinders, or clogged bleed bolts. Read P's post again.

Honda-Master

disconnect the brale line that goes into the wheel cylinder, have someone apply the brakes if a lot of fluid squirts out ,, you got a plugged wheel cylinder ,, if so replace them both,,,,if very little fluid squirts out , could be proportioning ( combination ) valve ,, but i have never seen a valve act up in tis matter

The Phil

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Honda-Master &raquo;</TD></TR><TR><TD CLASS="quote">disconnect the brale line that goes into the wheel cylinder, have someone apply the brakes if a lot of fluid squirts out ,, you got a plugged wheel cylinder ,, if so replace them both,,,,if very little fluid squirts out , could be proportioning ( combination ) valve ,, but i have never seen a valve act up in tis matter </TD></TR></TABLE>

Redundant.

Not sure how drums work, but you probably have a clog somewhere between the drum...actuating...whatever and the bleeder. Disassemble the unit and clean it.

hondadude

Hanyes manual is WRONG

tonezilla

ok, i took everything apart and found out that the wheel cylinders were all clogged up . cleaned them up and rebled the car and everything works fine now . thanks p_adams and everyone else who contributed .

P_Adams

Glad we ALL could help.
It's nice to know that we actually helped someone reach a satisfactory conclusion.
Thanks for the "That fixed it" report

P