8. (10 points) Among the three given phrases “尽心尽力” (exerting oneself to the utmost), “力可拔山” (strength to move mountains), and “山穷水尽” (at the end of one's resources), each Chinese character represents a number between 1 and 8. The same character represents the same number, and different characters represent different numbers. If the sum of the numbers represented by the characters in each phrase is 19, and “尽” (jin) > “山” (shan) > “力” (li), then the maximum value of “水” (shui) is $\qquad$
【Analysis】Through analysis, we can know:
From the three phrases “尽心尽力” (exerting oneself to the utmost), “可拔山” (capable of moving mountains), and “山穷水尽” (reaching the end of one's resources), the sum of the numbers represented by the Chinese characters in each phrase is 19. This gives us the equations:
$$
\left\{\begin{array}{l}
\text { Jin + Xin + Jin + Li = 19 (1) } \\
\text { Li + Ke + Ba + Shan = 19 (2) } \\
\text { Shan + Qiong + Shui + Jin } = 19 (3)
\end{array}\right.
$$
From (1) + (2) + (3), we get:
3 Jin + Xin + 2 Li + Ke + Ba + 2 Shan + Qiong + Shui = 19 × 3 = 57
The sum of 1 to 8 is 36,
So, 2 Jin + 1 Li + 1 Shan = 57 - 36 = 21, comparing with (1) we get Shan - Xin = 2.
“Jin” > “Shan” > “Li”, “Li” should be as large as possible, so “Jin” is minimized,
Assuming “Li”, “Shan”, and “Jin” are consecutive natural numbers, we have 2 (Li + 2) + Li + 1 + Li = 21
“Li” is 4, at this time Shan = 5, Xin = 3, Jin = 6;
(1) is satisfied: 6 + 3 + 6 + 4 = 19;
(3): 5 + Qiong + Shui + 6 = 19, Shui is maximized at 7, Qiong is 1, to solve (2):
(2): 4 + Ke + Ba + 5 = 19, and now only 2 and 8 are left, which satisfies the condition. At this time, Shui is maximized at 7.

But at this time, 6 (Jin), 4 (Shan), 5 (Li), does not satisfy “Jin” > “Shan” > “Li”, so it does not meet the requirements. Therefore, Shui is maximized at 7.

【Solution】Given that the sum of the numbers represented by the Chinese characters in the phrases “尽心尽力” (exerting oneself to the utmost), “可拔山” (capable of moving mountains), and “山穷水尽” (reaching the end of one's resources) is 19,
We can derive the equations:
$$
\left\{\begin{array}{l}
\text { Jin + Xin + Jin + Li = 19 (1) } \\
\text { Li + Ke + Ba + Shan = 19 (2) } \\
\text { Shan + Qiong + Shui + Jin } = 19 (3)
\end{array}\right.
$$
(1) + (2) + (3) gives:
3 Jin + Xin + 2 Li + Ke + Ba + 2 Shan + Qiong + Shui = 19 × 3 = 57
The sum of 1 to 8 is 36,
So, 2 Jin + 1 Li + 1 Shan = 57 - 36 = 21, comparing with (1) we get Shan - Xin = 2.
“Jin” > “Shan” > “Li”, “Li” should be as large as possible, so “Jin” is minimized,
Assuming “Li”, “Shan”, and “Jin” are consecutive natural numbers, we have 2 (Li + 2) + Li + 1 + Li = 21
“Li” is 4, at this time Shan = 5, Xin = 3, Jin = 6;
(1) is satisfied: 6 + 3 + 6 + 4 = 19;
(3): 5 + Qiong + Shui + 6 = 19, Shui is maximized at 7, Qiong is 1, to solve (2):
(2): 4 + Ke + Ba + 5 = 19, and now only 2 and 8 are left, which satisfies the condition. At this time, Shui is maximized at 7.

But at this time, 6 (Jin), 4 (Shan), 5 (Li), does not satisfy “Jin” > “Shan” > “Li”, so it does not meet the requirements. Therefore, Shui is maximized at 7.

Therefore, the answer is: 7.