Ek3 98 Non ABS break proportion valve

[sira]

Dear friends

I replaced my Break proportion valve few years ago due to imbalance break issue and that time i brought valve from spare part shop at dehiwala. See pic 1 and 1a. but now it is looks faulty again because i can feel that rear wheels get lock (rear left wheel). how ever when i checked this carefully i can see "67" on the unit and my old one got 40 . what does this means? when i checked on the web i can see 4040 proportion valve, but there is no valve for 67 . and also so numbers on the other side with different . what is the exact part number or specification for Ek3 98 model please

Thank you

 

[Rumesh88]

Proportionating valves are not known to fail that often? Do you have the stock brake arrangement for both front and rear or have you done any upgrade? If so you may have to go for a one like 30/40 perhaps because that gives more force to the front on hard braking than a 40/40 one.

[sira]

Hi Rumesh

Yes, i agree with you . when my original valve removed, the technician showed me the issue by dismantling the unit. there was grue in the piston head  this had happened when high presure break oil tries to go quickly to the rear wheels. I believe due to age of the car(15 years) these this can happen. so the new one (recon) i believe it warn too or different pressure .

see the attached pic of the 

I think  if i use the my original unit by turning the damage piston side to good side and use.

 

 

[Davy]

I can't believe the fairy tales mechanics tell these days.  Did you see the mechanic take the pistons out?

That damage on the piston could have not been causeb by excessive brake oil pressure. While your mechanic was trying to take the pistons out of the valve body, he must have inserted some sort or metal rod through the top 4 holes push the pistons back. That's the only logical explanation I see for the damage IMO.

As Rumesh said, these vales rarely become defective.  What exactly was the "imbalance issue" you had? Left-right or front-rear? 

Edited December 3, 2016 by Davy

[sira]

HI Davy

You are correct, i got same feelings.i was there at the garage when he remove the unit from the car and install the new one.may be he tamper this.

anyway, i dismantle the recon valve today . there wad no any damage on the pistons or other parts. what i also realized was the old unit piston rod also stuck with the base unit. it must be  freely moved.there is another rubber washer at the bottom of the spring too. just apply 2000 sand paper and cleaned the alloy rod and fixed it.looks fine

But did not use it. i fixed the recon one again and bleed. according to the manual , first RL, then FR, RR and FL. 

i can see difference now. the rear wheels now not get locked. previously RL will get locked at the morning with 20Km too.

It may be incorrect bleed process previously.

so i will test for few days and update. how ever new issue came. i can hear small cracking sound from the booster now. not sure where its coming from. will see

Thank you 

 

 

[Davy]

Glad it's working again. This is why the order of bleeding is very important. There might have been some air trapped in the RL line that caused that wheel to lock up.

[sira]

Hi

as mentioned above, i can hear a noise when i depress the break paddle. No other issue with the booster but noise

I showed to one of previous nissan tech at kottawa  and he used his automotive stethoscope and identified that the noise  coming from inside the break booster. so he said some boosters can repair may be need to apply silicon grease to the o'riigs...etc. But some cases it may verse then before. what is your recommendation of dismantle the booster ? 

Thank you

[Twin Turbo]

A question comes on the maintenance history os the car,.. When was the brake system last flushed?

Could your wheel cylinders/pistons be at fault?

 

[sira]

5 minutes ago, Twin Turbo said:

A question comes on the maintenance history os the car,.. When was the brake system last flushed?

Could your wheel cylinders/pistons be at fault?

 

The issue is now with break booster unit only.

 

[Twin Turbo]

The booster only pushes the master cylinder,..where's the noise?

 

[sira]

No!!! Booster will make the paddle smooth. it operate with vacuum . so when we press the paddle the booster rod will have additional power and presses the master pump.

 

 

[Davy]

The booster is a sealed unit and replacement is the recommended option if it's faulty. Apart from the noise you hear, is there a lack of power assistance or issue in the brakes?

[sira]

Hi Davy

after 8-10 hours when the engine is off  booster vacuum will go away. but that is not a big deal. when the engine is running the breaks are OK. no rear wheel lock at all.

The issue is the noise of the booster. i believe as the mechanic said, the master pump side O'rings or some rubber seal connected to the suction side may have warn. is it a risk to repair them? Honda dose have Booster repair kit which will cost 12K. my booster can be opened

sira

 

[Davy]

2 hours ago, sira said:

Hi Davy

after 8-10 hours when the engine is off  booster vacuum will go away. but that is not a big deal. when the engine is running the breaks are OK. no rear wheel lock at all.

The issue is the noise of the booster. i believe as the mechanic said, the master pump side O'rings or some rubber seal connected to the suction side may have warn. is it a risk to repair them? Honda dose have Booster repair kit which will cost 12K. my booster can be opened

sira

 

Vacuum usually goes away immediately after the engine is turned off.

Anyway, to determine if there is actually no problem with the booster, before you take things apart, perform the following test explained by Rumesh88:

 

[Rumesh88]

4 hours ago, sira said:

Hi Davy

after 8-10 hours when the engine is off  booster vacuum will go away. but that is not a big deal. when the engine is running the breaks are OK. no rear wheel lock at all.

The issue is the noise of the booster. i believe as the mechanic said, the master pump side O'rings or some rubber seal connected to the suction side may have warn. is it a risk to repair them? Honda dose have Booster repair kit which will cost 12K. my booster can be opened

sira

 

If the booster is serviceable (some are not!) then there is no risk in repairing it. It is not a complicated mechanism either. However, merely applying silicone grease is not a long lasting solution. First open the booster and see what has gone wrong. If you find only a worn out O-ring you can replace it with high quality O-rings used in hydraulic systems (I did a similar repair in a KE20 booster sometime back). It is always better to use the original repair kit but if it is just one O-ring spending 12k could be a bit of an overkill. 

[sira]

Thanks Rumesh

I dismantled the booster and couldn't find any warn or corroded area. then i swap my old  Proportion valve. The noise coming from the proportion valve finally . I swap this one in 2013 due to imbalance break issue ,

how ever i managed to fix my stock one . it had grue on piston head  and piston rod stuck (as i explained above) but i managed to fix it and swap it .

the noise has gone but I feel some little difference on rear breaks. it does not locked at all , but it looks break force is low now. at around 40 KMPH with previous valve, front wheels dose not locked and cars stops smoothly. now i can see the front wheels locks and it skids. dose not seems that rear wheels get good force. very disappoint now!! . because it really hard to find 6 line proportion valve these  days.

 

[Davy]

How much free time do you really have to be doing all these experiments?  I thought your "mechanic" used his stethoscope and found that the noise is coming from the booster? Good mechanic you've got there. 

Symptoms of a bad booster are usually quite obvious and you can tell without taking the booster apart by simply doing the aforementioned test. It's just a waste of time taking it apart.

To be honest, I'm not surprised it doesn't work still. Combining parts from two defective units to make one "working" unit doesn't guarantee that it will work. At this point, I think your best bet is to just find a new proportioning valve. If you know the part number, you should probably try Amayama or Partsouq.

 

These are your next steps IMO:

1. Find new proportioning valve and install

2. Inspect rear brakes and ensure handbrake mechanism is okay and working. Do a general inspection of all wheels.

3. Bleed brakes (all wheels starting from the furthest wheel to the master cylinder to the closest one. or follow manual if you have one). Use new brake fluid.

4. Check for vacuum leaks

5. Perform booster test again (quoted post above)

6. Test drive

[sira]

4 hours ago, Davy said:

How much free time do you really have to be doing all these experiments?  I thought your "mechanic" used his stethoscope and found that the noise is coming from the booster? Good mechanic you've got there. 

Symptoms of a bad booster are usually quite obvious and you can tell without taking the booster apart by simply doing the aforementioned test. It's just a waste of time taking it apart.

To be honest, I'm not surprised it doesn't work still. Combining parts from two defective units to make one "working" unit doesn't guarantee that it will work. At this point, I think your best bet is to just find a new proportioning valve. If you know the part number, you should probably try Amayama or Partsouq.

 

These are your next steps IMO:

1. Find new proportioning valve and install

2. Inspect rear brakes and ensure handbrake mechanism is okay and working. Do a general inspection of all wheels.

3. Bleed brakes (all wheels starting from the furthest wheel to the master cylinder to the closest one. or follow manual if you have one). Use new brake fluid.

4. Check for vacuum leaks

5. Perform booster test again (quoted post above)

6. Test drive

Thank you for the complements i had a long holiday   

The mechanic is one my friend at kottawa and he used his stethoscope to found the noise, i know him since 2006 as he fixed my FB 13 he was a good mechanic .but this time he was wrong. 

anyway. i have found a guy who import this item and his cost is 10K.

I think i will need a bleed this valve before connect out lines . may be  try like bench bleed like we do for master pump. I just found a slimier type of design this called  "Sumitomo type proportioning valve . see attached.

hopefully not going to use a  recon one because if its make any issue it will waste my time again . Couldn't find the such a long weekend in future ....

Thank you for the update

sira