Brakes Argh!!

[Banjo57]

Been busy - Replaced all Shockies with Terrafirma - Replaced rear brake shoes, cylinders and drums - completely bled them.
Now when I apply the brakes I get an oscillation (shudder) through the pedal.
Any ideas, it's giving me the s..ts, I don't know what it could be?
Put a dial gauge on the discs and they are running true.
Help!

[Ravvin]

I had this with a Hilux many years ago, but it was a buckled rotor that time.
When you say you put a dial gauge on the discs, did you check both sides? As in the face AND back of the rotor?
If the fronts are good, you could have an out-of-round drum on the back. Quick way to check would be to block off the pipes to both back wheels. Use a blind rivet in the pipe to the slave cylinder, both sides. If that stops it, it is one of the rears. Next step would be to take the rivet out of one side and check again. That will tell you which side is dodgy.

Another possibility, although a slim one, is that you may have a proportioning valve in the line to the rear brakes. I've seen one type that has a spring and ball bearing in it that only allows fluid past once the pressure is above a certain point, guaranteeing that the fronts get the majority of the braking force. If the spring is failing or there is corrosion or gunge in the valve, it could make it grip and grab, which would feel like pulsing.
This is just a thought, as I don't know what system your Landy has, but I thought I'd mention it just in case.

Greg.

[AlexR]

Had this problem with mine and it was due to wheels being out of balance

[Banjo57]

Thanks guys - Brand new drums and pads on the back.

[fc101]

Have you have the rear shoes the right way around - there is a specific shoe that is the leading shoe and one that is the trailing shoe - put in the wrong way around and various issues can result.

[Banjo57]

That's a interesting solution, Thanks garrycol!
How do you tell the difference?

[BadCo.]

I suggest you do a google search, you might find a write up or video guide on replacing defender drum shoes.

[Banjo57]

When replacing the shoes pair up a leading shoe with a trailing shoe. The leading shoes are the ones with the posts that face the backing plate and ride on the adjuster cams. The trailing shoes have no posts. Apply a bit of grease (preferably white lithium assembly grease) to the top and bottom of each shoe where they come in contact with the cylinder pistons and the bottom pivot bracket. Also apply some grease to the edge of the adjuster cam and to the two points on the backing plate that come in contact with the shoes. Do not allow any grease to get on the brake linings!

[Banjo57]

Still no luck or knowledge of fixing the problem?
Did Perenties come out of the womb with ABS?

[BEARMAN]

Still no luck or knowledge of fixing the problem?
Did Perenties come out of the womb with ABS?

You mean Automic Brake Slackness!!!!!!
No only the ones with brake drums on the rear

[Philthy]

Been away so the reply might be late.

Recheck the mating faces between the front disks and the hub if you did them. Mating faces must be spiffy clean and true.

If you think its coming from the rear. Reinstall just the old drum's. If it stops return the drum's.

Hate to say it but there is some crapy aftermarket drum's and rotors around.