crappy Defender brakes

**Huwmungus** · 18th May 2007, 05:43 PM

I'm Glad my 130 Fender isn't the only one with crap brakes, they are nowhere near as good as the ones that were on the disco. Mine are similair symptoms to wally. You seem to get to a point whilst braking that you would expect it to grab harder but it doesn't. I've bled the brakes and checked for vacuum, seems ok. The pedal is harder than the disco. I'm still sus about the vacuum pump. I've nearly ran up a few rears (driving as if I were in a disco)until I got used to them. I haven't had the Fender long and am yet to investigate more.

**George130** · 18th May 2007, 07:14 PM

You will know when there is no vacume!
I broke the vacume line on mine and the peddle was like a brick. Stopping was a real challenge and required advanced warning!

**JDNSW** · 18th May 2007, 07:45 PM

Originally Posted by George130

You will know when there is no vacume!
I broke the vacume line on mine and the peddle was like a brick. Stopping was a real challenge and required advanced warning!

Yes, but less obvious is when there is some vacuum, but not as much as there is supposed to be. The symptoms sound to me more like a vacuum leak, which may be in the booster or could be in the plumbing. Same effect could come from a blocked vent on the booster as well.

John

**kie4** · 18th May 2007, 08:17 PM

Hi, check very carefully around the area where the master cylinder bolts to the booster, the booster may be cracked. it will seem ok until you put your foot on the brake then the crack opens up and lets air in. I have changed loads of these for this problem. often hard to see though...
Rich

**justinc** · 18th May 2007, 11:04 PM

Originally Posted by kie4

Hi, check very carefully around the area where the master cylinder bolts to the booster, the booster may be cracked. it will seem ok until you put your foot on the brake then the crack opens up and lets air in. I have changed loads of these for this problem. often hard to see though...
Rich

Yup, I've fitted heaps due to cracking. Don't try to fix them, they are only about $300 for a new one. I've seen silastic and even liquid nails been tried to seal up the cracks!!

JC

**Blknight.aus** · 19th May 2007, 04:29 AM

to further jusincs point...

you can use the sealastic type stuff to get yourself home... but you must wait for it to fully cure or its going to get sucked into places you dont want it to be.

faffing around repairing a cracked booster is more hassle than its worth.(and more costly than replacing it with a new one).

The average vaccume (used on a gauge that reads absolute pressure not gauge pressure IE sits on 14.7psi when in normal atmosphere) on 3 of the army 110s is -7 to -8 psi whatever that is in MM Hg I dont know but will redo it when we get the vac gauge at work repaired.

**rick130** · 19th May 2007, 06:14 AM

they use a different booster to a Defender, don't they Dave ?
Wasn't it a double diaphragm F250 one ? or is that the 6x6's ?
Or is the working vacuum the same ?

**JDNSW** · 19th May 2007, 06:19 AM

Originally Posted by Blknight.aus

to further jusincs point...

you can use the sealastic type stuff to get yourself home... but you must wait for it to fully cure or its going to get sucked into places you dont want it to be.

faffing around repairing a cracked booster is more hassle than its worth.(and more costly than replacing it with a new one).

The average vaccume (used on a gauge that reads absolute pressure not gauge pressure IE sits on 14.7psi when in normal atmosphere) on 3 of the army 110s is -7 to -8 psi whatever that is in MM Hg I dont know but will redo it when we get the vac gauge at work repaired.

14.7psi absolute is the same as 760mm - so 7psi absolute will be about 361mm, but again you have to be sure you are talking absolute pressure - i.e. gauge on 760 at atmospheric, otherwise subtract from 760.

John

**PAT303** · 19th May 2007, 07:20 AM

I am going to fit EBC grooved rotors and green stuff pads to my disco and they look the goods. Pat

**Blknight.aus** · 19th May 2007, 06:47 PM

the vac pump on the alternator is essentially the same so your after the working pressure...

(this is for an isuzu but the principal is the same)

grab a compound gauge and pull your vac line to pieces..

start fresh of the vac pump and see what it draws.

install the next hose (should go from the pump to the rigid line that runs across the back of the motor)

check it from that hose.

connect that hose and check it from the other side of the rigid line across the back, if its low there then more than likely you have a leak from the diff lock actuation line or valve, most common is the line rubbing on either the bottom of the air filter if it is too long or the fire wall if it is too short.

then check the flex line to the booster without the oneway valve and strainer fitted
then check it (if you have the gear from the strainer and the one way valve..

with the engine idling there should be no difference in the best reading you get but it will take marginally progresively longer to get there as the pump doesnt shift masses of air.

have someone with a meaty right leg apply the brakes for you after they pump them up for 3 pumps, if your firewall is flexing you will see the booster and master cylinder move you should also notice that your pedal tower is deflecting a bit as well..

that being the case you need to put a re-enforcement plate on the firewall and plates on the pedal tower...

making the firewall re-inforcement plate is a simple as getting an old dead pedal tower and cutting the flange of, dressing it and putting it in on the inside of the cab.

Alternatively grab a spare sealing gasket goto a good metal worker and say make that for me in 2mm or better mild steel. TY

Should cost $70ish

the 130s are also a bitch to bleed and if youve done them without a pressure or vacume bleeder you may have allowed air in.

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