DUKE LADUKE

I just got stainless lines and new brakes on my car . They were bled properly and are doing still what they were originally doing . When I push my brake pedal down my idle increases?.. what would cause this? Also, the pedal takes longer to push down and is almost squshy .

Vaccum leak ?

Brake booster?

Master Cylinder?

98civdx

i heard the stainless lines can cause the differnce in peddle feel you are feeling.
Mine does this every now and again and i have never noticed a vaccum leak,

you can always test but pulling off your intake tube and while the cars runing hold your hands over the tb make sure there is no gaps. if the engine keeps runing there is a leak if it dies there is not.

DUKE LADUKE

deff a leak .. but what would cause it ?

brake booster ?

tuck1crx

did u accadentaly flip the check valve on the vaccum line?

DUKE LADUKE

nope . Its facing the right way

tuck1crx

pedel hold or drop?

DUKE LADUKE

when you push the pedal down to stop, Its a longer push to stop. Under high speeds the pedal will vibrate rapidly. Also when you step on the brake pedal at idle you can see the idle increase.

v8killaz

yeah idle increase is normal, its called vaccum. the pedal vibration is caused most likloy by bad rotors. buy some oem honda ones dont get aftermarket bs they suck *****.
mushy felling could be air in the system. bleed the brakes properly(all 4 wheels in the right order)

DUKE LADUKE

But jump from 1000k -1500 rpm?

v8killaz

does it come back down, ur idle is at 1000 u have bigger problems

DUKE LADUKE

It does go down ..neptune was set like that . its about 900 rpms

96hb

My car does the same thing and has done so ever since I bought it. I always just thought it was normal.

v8killaz

yeah it should be fine, mine goes up maybe 300 rpm or so when i pump the brakes. its normal. You dont want it going down is whats bad, ur car would stall or hesitate everytime u brake

s13hero

Happened to me when I was having problems with my brake booster

Koopa Troopa

No it won't.

You have air in your lines.

Cain Marko

the rpms would increase on my car when i was sitting still and pumped the brakes, its just revving the motor to create more vacuum for the braking system, but the mushy pedal, bleed those bastards, get a power bleeder or something, make your life easier

eghatch420

I thought RPMs increase when you press brakes because it uses some engine power to use the power brakes (hydraulic). When I'm sitting at a light, and I push pretty hard (not abusively) on the brakes, my RPMs raise about 4-500 RPMs. From like 7-800 RPMs to about 12-1300 RPMs. If this is not supposed to happen then I have a problem too! But as far as I've heard, just like with some power steering setups, it raises your idle a little.

v8killaz

power steering i think lowers it but the car recognises the lower rpm and raises it quickly to compensate.

Koopa Troopa

It uses no engine power to use your brakes and they are not power assisted. Your brakes are vacuum assisted, hence the brake booster. Which is why engine idle will fluctuate when you use your brakes while no load is on the engine, vacuum is changing and causes the engine speed to fluctuate because of an increase/decrease in vacuum

DUKE LADUKE

It was the check valve. The original one **** the bed , picked one up from honda for 30- and now its fine !

Thanks guys

instructor74

whats fixed the idle problem, the mushy brake pedal, or the pulse when brakes are applied?

DUKE LADUKE

Idle issue and mushy brake pedal .. check valve

Warped rotor caused the vibration.. fixed

iboughtas2k

Can you make what the "check valve" more clearly?
And where its located?
Cuz mine does same and I wanna replace the check valve

Wdpfreak145

Check valve is a one-way valve in the vacuum line running from the intake manifold to the brake booster. It prevents vacuum from being forced back when you push the pedal. If its bad it will let back prrssure out and the pedal will feel squishy

Alvarado1228

if you want to find a leak, get some tb cleaner and spray on the areas where leak could be a problem. watch out tho, its not the safest of things to do cause it combustible, but when you find the leak the engine should sputter b/c of the cleaner.