BMW 1989-1995 525i Service Manual page 16

010-8
FUNDAMENTALS FOR THE DO-IT-YOURSELF OWNER
Many reputable tool manulacturers offer good quality. mod -
erately priced tools with a liletime guarantee. A broken tool can
be exchanged lor a new one. lor the life 01 the tool. These are
your best buy. They cost a little more. but they are good quality
tools that will do what is expected 01 them. Sears' Craftsrnarr"
line is one such source 01 good qua lity. reasonably priced. and
guaranteed tools.
Some
01
the repairs cove red in this manual require the use
01
special tools. such as a custom puller or specialized electrical
test equipment. These special tools are called out in text and
can be purchased through an authorized BMW dealer. As an
alternative. some special tools mentioned may be purchased
Irom the lollowing tool manufacturers and/or distributors:
• Assenmach er Specialty Tools
6440 Od ell Place. Boulder. CO B0301
(303) 530-2424
• Baum Tools Unltd. Inc.
P.O. Box B7. Longboat Key. FL 3422B
(BOO) B4B·6657
• Schley Products Inc.
5350 E. Hunter Ave.• Anaheim Hills. CA 92B07
(714) 693 -7666
• Zelend a Machine and Tool Corp.
66-02 Austin Street. Forest Hills. NY 11375
(71B) B96-22BB
Basic Tool Requirem ents
The basic hand tools described below can be used to accom-
plish most 01 the simple maintenance and repair tasks.
Screwdrivers. The common flat-blade type and the Phillips
type will handle almost all screws used on BMWs . Two or three
different sizes
01
each type will be best. since a screwdriver
01
the wrong size will damage the screw head. See Fig. 7.
A complete set 01 screwdrivers should also include Torx®
type screwdrivers.
Wren ches. Wrenches come in different styles lor different
uses. Fig. 8 shows several. The basic open-end wrench is the
most widely used. but grips on only two sides .
It
can spread
apart and slip all more easily. The box-end wrench has better
grip. on all six sides of a nut or bolt.
A 12-point box-end can loosen a nut or bolt where there is
less room l or movemen t. while a 6-point box-end provides bet-
ter grip. For hex fasteners on fluid lines. like brake lines and fuel
lines. a flare-nut wrench offers the advantages 01 a box-end
wrenc h with a slot that allows it to lit over the line.
The combination wrench is the most universal.
It
has one
open-end and one box-end. 10mm and 13mm wrenches are
the most common sizes needed. A more complete set
01
wrenches would include 6mm through 19mm sizes.
TOOLS
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BOOSfNO
BO05.FNG
Fig. 7. Common flat-blade (top) and Phillips (bottom) screwdrivers.
Onset screwd river (right) is used for screws with limited access.
BOO2FNG
B002FNG
Fig. 8. Types of wrench heads. From left. open-e nd. 12-point box -
end. 6- point box-end. flare nut.
Sockets. Sockets perform the same job as box -end wrench -
es. but offer greater flexib ility. They are used with a ratchet han-
dle lor speed and convenience and can be combined with
extensions and universal joints (swivels) to reach lasteners
more easily. Sockets come with different size connections to
drive handles or extens ions. called the drive size . The most
common drive sizes are 1/4 in.. 3/8 in.• and 1/2 in.
Sockets come in 6-point and 12-point styles. For use with a
ratchet. the 6-point offers a better grip on tight nuts and bolts.
6mm to 19mm sockets are the most needed sizes. Below is a list
of typical bolt diameters and the corresponding wrench sizes.